Emu Hojo

Emu Hojo (宝生 永夢) is a 24 year-old pediatrician and surgical intern at Seito University Hospital who is also secretly the genius gamer M. Because of his status as Patient Zero of the Bugster Virus, he was able to use the Gamer Driver without the required surgery and become Kamen Rider Ex-Aid (仮面ライダーエグゼイド). As a doctor of CR, he is mainly tasked as Ex-Aid with eliminating the Buster Virus from infected patients in order to save their lives.

Childhood
Emu developed interests in video games at the mere age of 8, which he proved to have a natural talent for in the near future. This lead him to creating the concept for Mighty Brothers XX, to ease his loneliness. From a young age, he was a huge fan of Genm Corp. and often sent fan letters to one of its programmers, Kuroto Dan, which had included ideas for new games. Furious that someone who could create game concepts on par with him, Kuroto sent Mighty Action C, a game in-development which, unknown to anyone but Kuroto, had been infected with a strain of the Bugster Virus, which subsequently infected the boy.

On one rainy day, Emu succumbed to the Bugster Virus and subsequently got involved in a traffic accident. After receiving an emergency surgery from Kyotaro Hinata, Emu was given a WonderSwan handheld video game device by Dr. Hinata as a reward for hanging on. This event would inspire Emu to become a doctor and help children like the one who saved him.

Teenage Years
Emu would later go on to win numerous gaming tournaments under the gaming alias of M. Sometime in 2010, Emu trained vigorously for a gaming tournament he had participated in, at the cost of his health. Unknown to him, Kuroto watched his victory in the shadows, having watched Emu for a decade. Shortly after, Emu was abducted by the Next Genome Institute, who had been hired by Kuroto to remove the now-mature Bugster Virus from Emu's body. After the matured Bugster later known as Parado was successfully removed from Emu's body, the members of the Next Genome Institute vanished. Emu would believe that the operation was nothing more than a dream. Following the incident, he decided to take a serious attitude in his entrance exam and pursue being a doctor. However, the leftover Bugster Virus in his body would create a split personality that represented his gaming interest. The Bugster Virus that had been extracted would be used as the basis for the virus used for Zero Day a year later.

Sometime later, his fame as "M" would earn the interest of Asuna Karino as a potential candidate for using the Gamer Driver.

Becoming Kamen Rider Ex-Aid
Emu eventually became a pediatrics intern at Seito University Hospital. After it is learned that his patient, Sota Suyama, is diagnosed with an unusual disease, he is restricted from knowing more by Director Haima Kagami. Emu deduces that Sota's stress may be related to being confined in the hospital and unable to see the release of the awaited video game, Mighty Action X. As a result, Emu takes him to see its release but is scolded by Asuna, telling him that he fails as a doctor for his unauthorized release of Sota. When Asuna tries to force Sota to return back, his condition worsens and he transforms into a golem-like creature.

Emu learns about Sota's condition of being infected with the Bugster Virus, a potential lethal computer virus that infects human, and can be prevented by someone who is capable of using the Gamer Driver to successfully operate on the patient. Determined to save his patient, Emu took the driver, the accompanying Mighty Action X Gashat without Asuna's consent to combat the Bugster. Much to Asuna's surprise, Emu was able to transform into as he reveals that he was in fact, the prodigy gamer "M" that she was looking for.

He extracts Salty from Sota and transforms into Action Gamer Level 2, defeating the Bugster. After confirming Sota's health, he becomes part of the CR and Asuna reveals to him that her true identity is a Kamen Rider navigator, Poppy Pipopapo. She christened Emu as Kamen Rider Ex-Aid.

As the battle against the Bugster Viruses continues, Emu would later meet several Kamen Riders like him, such as the genius surgeon Hiiro Kagami (Brave), former CR acquaintance Taiga Hanaya (Snipe) and the coroner Kiriya Kujo (Lazer). Although the three Riders as well fought against Bugster threats and infections, Emu is constantly at odds with them as each had their own viewpoints and ulterior motive. He also faced against Genm, a Rider who allied himself with the Bugsters and at the same time adding another Gashat, Gekitotsu Robots to his arsenal. In the final battle against Graphite, Emu acquired the Drago Knight Hunter Z and is able to work in synchronization with the other Riders through this power.

Level X and Emergence of Para-DX
During Christmas Eve, Emu and the others learned of Genm Corp. CEO Kuroto Dan being Genm's true identity, proving Kiriya's innocence after being fooled once by Parado. It was also at that time he renew his trust on Kiriya after going through several lies and obtain the Shakariki Sports Gashat from Genm but their renewed friendship cuts short when Kiriya was killed by Genm Zombie Gamer Level X in hopes of preventing the truth from being revealed.

"Emu Hojo!!! How are you able to transform into Ex-Aid...without undergoing the compatibility surgery? How are you able to create Gashats?! Why does your head hurt after transforming?! There is only one answer. Emu Hojo! That's because...you were the very first person in the world...to be infected by the Bugster virus!" "I have Game Disease...? No way...you're just trying to trick me."

- Emu Hojo learns that he is Patient Zero of the Bugster Virus

In early 2017, Emu was promoted to the surgery intern by Haima Kagami himself. Kiriya's death affected his prowess in fighting the Bugster and was suspended by Hiiro to transform after the latter confiscated his Gashats. Parado approached Emu and gave the young intern his incomplete Gashat, which transformed into the Mighty Brothers XX Gashat, giving him the strength to counter Genm Level X with the same rank. He as well renewed his trust with Hiiro, but was cut short when both the latter and Taiga attack him due to being a Game Disease patient. His combat data as Mighty Brothers XX was utilized by Kuroto to create the Gashat Gear Dual that Parado utilized to assume Kamen Rider Para-DX, whose level outclassed even that of Genm and Ex-Aid. After a chain of events that involved Genm Corp. member Tsukuru Koboshi as a victim, Emu experienced a fatal outburst of Bugster Virus when Kuroto revealed his true background as Patient Zero. This almost cost his life if it was not for Parado taking possession before he regains consciousness from Hiiro's own words.

Kamen Rider Chronicle and Level 99
After recovering from his doubt, Emu resumed the fight with Genm and learns too late that he and the other riders were used to further the creation of Kamen Rider Chronicle and unlocking Dangerous Zombie's potential as Level X.  His kindness was exploited by Kuroto again to harvest Charlie Bugster and escaping from the authorities, who in turn destroyed his Gamer Driver. With Kiriya's own Driver and a new Gashat developed by Tsukuru, Emu obtains Maximum Mighty X and puts Kiriya's reprogramming research to use so as to counter Genm's abilities. Although he managed to strip Kuroto of his powers, Emu's efforts were all for naught when Parado killed him with Dangerous Zombie's own power.

After an encounter with and completing his surgical internship, Emu was horrified to discover that Poppy was brainwashed into becoming a part of Kamen Rider Chronicle, now under the ownership of the Bugsters, led by the new Genm Corp CEO Ren Amagasaki/Lovelica Bugster. Although he and the rest of the doctors were told to not interfere with Chronicle, Emu eventually went against the order to save the Ride-Players despite their refusal. Taking into account of how Poppy smiled towards Taiga and Nico Saiba's growing relationship, Emu successfully saved and cleared her Level after a tearful reconciliation. Poppy likewise would return the favor by saving him from Parado's control after being tricked into providing the latter with his own DNA and forced to fight towards the point of exhaustion. This assistance came in the form of a revived Kuroto, forcing CR to form an uneasy alliance with him to clear Kamen Rider Chronicle.

Advent of Cronus and Hyper Muteki
As CR faces off against the high tier Bugsters, both sides find themselves facing against Masamune Dan, Kuroto's father, who reveals himself to be the true mastermind of the events that have unfolded and utilizes the Master Gashat of Chronicle to become Kamen Rider Cronus. Because of his exploitation in the use of Pause and holding the Proto Gashats (and by extension, victims of Game Over Ride-Players and Game Disease) hostage, Hiiro was lured into working for him, forcing Kuroto to create the Hyper Muteki Gashat as a counteract. Said Gashat however failed due to Parado's reprogramming until a combination of Emu and a revived Kiriya's tactic allowed him to assume Hyper Muteki, as well as regaining the stolen Proto-Gashats.

Because of Hyper Muteki, Emu was blackmailed by Masamune in multiple occasions, first by putting Saki Momose's data and later Nico's life in jeopardy. Hiiro willingly returned to CR at Saki's expense while Emu brutally "killed" Parado, seemingly at the cost of his own transformation. As it seemed that the tides of battle returned to Masamune, the genius gamer revealed to have saved Parado's data within himself and revived him as he finally makes peace and joins forces with his former enemy. Despite the destruction of the Master Gashat, Masamune managed to use Reset and restore it, therefore negating Hyper Muteki's existence. However, Kuroto recreated it again, this time with a "Save" function to save their progress and bring forth the last boss Gamedeus.

Final Battle against Gamedeus and Cronus
With Gamedeus and his Bugster Virus pandemic spreading rapidly, Ex-Aid and Para-DX fought against him while the other doctors stayed behind to take care of the patients. Although the Doctor Mighty XX Gashat developed by Kiriya and Kuroto managed to weaken him, Masamune barged in at the last minute and absorbed the Bugster into his own body. This resulted in the fusion known as Gamedeus Cronus, proclaimed to be Chronicle's true final boss, reigniting the pandemic and turning his victims into Bugster Viruses until Poppy sacrificed her life with the Doctor Mighty XX Gashat. Para-DX would follow in suit by holding off Super Gamedeus as the Level 1 Riders separated him from Masamune, sacrificing both his existence and Emu's transformation. As all hope seemed lost, Emu miraculously regained his infection and dealt a punch towards Cronus' Buggle Driver II, permanently disabling Pause. He and the remaining Riders transform and finish Cronus once and for all. However, in a final attempt to gain an edge over the Riders, Masamune inserted the Master Gashat into himself and died, thus removing the only way to rescue the data of the patients within the Proto Gashats. Despite that, Emu remained confident in his belief that the advancements in medical science would one day allow the data to be rescued, as he presented to a press conference alongside Deputy Director-General Kyotaro.

One day, while Emu returned to CR, he discovered that Poppy was revived by Kuroto from what was left of her data. Kuroto later revealed that the same occurred with Emu and Parado, which was why he was still able to transform during the final battle. Emu rejoices at the fact as Parado re-emerges from him as the two share a reunion, before Emu goes to take on another medical case.

Island of Eyecons
Earlier from Ghost's perspective, Ex-Aid inexplicably appeared on the Island of Eyecons as Takeru and his friends were being pursued by the Gamma. His mere arrival extinguishing the Gamma Commandos, Ex-Aid introduced himself to Takeru before performing a successive Rider Punch and Kick to destroy a pair of Gamma Superiors. Allowing Takeru and company to get away, Ex-Aid faced off against Kamen Rider Dark Necrom B, whom he overpowered with a series of kicks and punches while empowered by the green Ex-Aid medals that accompany him before defeating the Dark Necrom with the Mighty Critical Strike.

Kamen Rider Ghost
Searching for the Shakariki Sports Gashat which he needed to save the world, Ex-Aid arrived to fight a pack of Bugster Viruses which were being fought by Ghost in defense of Ayumu, the mysterious boy who held the Gashat. Mistaken for an enemy by Ghost, whose friends had been attacked by his doppelganger, Ex-Aid found himself attacked but was quickly able to reason with his fellow Rider as he explained that he wished to save lives - the most important thing of all - by changing fate, a sentiment which was respected by Ghost. Alongside Ghost, Ex-Aid tended to Ayumu as they were attacked by his doppelganger, Kamen Rider Genm, who took the Gashat before leaving as soon as he came. Ghost apologized but Ex-Aid assured him that it was alright for now as Ayumu was safe. After defeating a further horde of Bugster Viruses together, Ex-Aid predicted to Takeru that they would meet again soon before leaving him an Ex-Aid Ghost Eyecon as a gift as he took his leave, with Takeru noting that he had connected to another person's feelings.

Kamen Rider Ex-Aid "Tricks": Virtual Operations
At the request of Kuroto Dan, Emu entered the CR patient room where he was to undertake a simulation as the Action Gamer. Given Dan's VR device by Poppy Pipopapo, Emu was clueless as to how he would start only to enter the simulation having been knocked out by Poppy. Within the simulation, Emu was faced with generic Bugster Virus grunt. Instructed by Poppy, Emu transformed into Kamen Rider Ex-Aid Action Gamer Level 1 then Level 2 before activating his Critical Strike finisher using the Kimewaza Slot Holder. Having cleared the simulation, Emu received no explanation for why he had to take this test as Poppy left, attempting to go after her only to stumble from the bed.

Kamen Rider Heisei Generations: Dr. Pac-Man vs. Ex-Aid & Ghost with Legend Riders
Following the intrusion of the Next Genome Institute into Genm Corp. headquarters, Emu would meet Takeru again as the two Riders face off against the threat of the Pac-Man Virus. The two would later on be aided by Wizard, Gaim, and Drive in defeating the Institute. During the battle, Michihiko Zaizen revealed that he was the one who operated on and infected Emu with the Bugster virus, and inserted both the Mighty Action X Gashat and its prototype counterpart into Emu's Gamer Driver in order to send Emu into the Game World. However, the massive infection from the Gashats would instead allow Emu to transform into his Level XX form for the first time. The memories of the final battle along with the revelation would be erased from Emu, due to the trance-like state he was in during the final battle. Emu would later re-learn the truth about his Bugster infection much later.

Kamen Rider Ex-Aid "Tricks": Kamen Rider Genm
Following the incident with Dr. Pac-Man, Emu was instructed by Dan to return the Kaigan Ghost Gashat. On his way to Genm Corp. with Asuna, Emu was met by a Collabos Bugster which wielded the power of the Proto Gashats and easily overwhelmed Ex-Aid when he assumed Ghost Gamer Level 2 again. It was at this point where Dan arrived with a briefcase carrying further Kamen Riders' Gashats, providing Ex-Aid with the Full Throttle Drive which allowed him to disarm the Bugster of the Proto Gekitotsu Robots Gashat. When the Bugster switched to the sword-wielding Proto Giri Giri Chambara Gashat and grazed Dan, Ex-Aid appropriately received the Toukenden Gaim to engage it as Asuna took Dan to safety. After disabling the Bugster, Ex-Aid was confused to see what he recognized as the "black Ex-Aid" adopting Wizard Gamer Level 2 before being swiftly defeated by the enigmatic Kamen Rider who announced that he had collected all the data he needed as he used the power of the Legend Rider Gashats to complete his Ganbarizing Gashat. Using the blank Collabos Bugster as a conduit to harness the power of Kamen Rider Battle: Ganbarizing, a game Emu was unfamiliar with, Genm brought forth manifestations of Kamen Riders Double, OOO and Fourze. Advancing on Emu, the three Riders were held off by the sudden appearance of Dr. Pac-Man, coming as a shock to both Emu and Genm as he presented his own three Bandai Namco Gashats.

Taken away by Dr. Pac-Man, Emu was met by Hiiro and Taiga whom were both intent on defeating this revived "Dr. Pac-Man" while Emu began to trust him. When the three doctors were met by Genm and the three copy Kamen Riders that he had summoned, "Dr. Pac-Man" provided the trio with the Bandai Namco Gashats, with Emu receiving the Pac Adventure Gashat. Transforming, Ex-Aid Level 2 faced Kamen Rider Fourze in a brief skirmish before using his new Gashat to assume Pac Action Gamer, generating a Game Area in which he finds himself pursued by Kamen Rider Double before reaching a Power Pellet which allowed him to turn the tables on Double who became a vulnerable ghost, performing Pac Adventure's Critical Strike to defeat the opponent Kamen Rider. Confused to be met with no Game Clear message, Ex-Aid returned to the real world where he saved Poppy Pipopapo from the berserk Collabos Bugster from whom he took out the Ganbarizing Gashat which he inserted into his Gashacon Breaker, performing a Critical Finish to destroy the Bugster. Despite this, both Ex-Aid and Poppy found that a Game Clear message has still not appeared. The Ganbarizing Gashat then suddenly ejected from the Gashacon Breaker on its own before entering the Game Area from which a figure began to emerge.

Ex-Aid recognized this figure as another Kamen Rider, Hibiki, while Poppy mistook him for a malicious demon and ran away. Immediately after, Ex-Aid was met again by "Dr. Pac-Man" but noted no sign of the black Ex-Aid pursuing him as he was handed the Taiko no Tatsujin Gashat, which Ex-Aid recognized as a music game where the goal is to hit the taiko drum in time with the rhythm, realizing that he could use this to face the drummer Rider. Inserting the Gashat into his Kimewaza Slot Holder, Ex-Aid was armed with two taiko sticks which he used to match Hibiki's Ongekibou Rekka before blasting back and finishing him with Taiko no Tatsujin's Critical Strike, at last clearing the game. Recovering the Ganbarizing Gashat, Ex-Aid was met by rival Riders Brave and Snipe, who had both come to claim the Gashat for themselves only for all three Riders to be swiftly eluded by "Dr. Pac-Man" who snatched the Gashat himself, adding it to his collection now totaling five. It is at this point that Snipe and Brave realized that they had been manipulated and used as guinea pigs, a deduction immediately confirmed when "Dr. Pac-Man" was joined by the black Ex-Aid, who took the Ganbarizing Gashat for himself. Inserting the Gashat into his Kimewaza Slot Holder, Genm activated a Critical Strike which imbued him with the combined power of Ex-Aid's seventeen Heisei Rider predecessors, allowing him to defeat all three Riders with a single Rider Kick. Genm then took his leave with the Gashats as Emu wondered what exactly was going on.

Kamen Rider Brave: ~Let's Survive! Revival of the Beast Rider Squad!~
At Seito Hospital, Emu bumped into an unidentified man. Unbeknownst to him, he had been caught up in the plot of the enigmatic Foundation X, having had their own Level 4 Gashat, Night of Safari, slipped into his pocket. This led Emu to being confronted by the revived serial killer - Kamen Rider Ouja - Takeshi Asakura, who was after the Gashat as part of his sick "game" before becoming bored and proceeding to give Emu a savage beating. Emu would be found unconscious and badly injured by Hiiro, who took the Gashat still in his hand, using it to assume Brave Safari Quest Gamer Level 4 with which he defeated Kamen Rider Ouja and his Beast Rider Squad.

Through the use of an Ex-Aid that inexplicably had been acquired by, Kamen Rider Ex-Aid was summoned to a version of the world which had been occupied by the , coming to the assistance of the   and  whose battle against Jark Matter forces had been interrupted by Space Ikadevil, a cyborg monster of Shocker. First appearing as Action Gamer Level 1, Ex-Aid fought off Space Ikadevil, allowing Sasori Orange to get away. Switching to Level 2, Ex-Aid joined forces with Shishi Red and together they used their respective slash attacks (Mighty Critical Finish and Regulus Impact) to destroy Space Ikadevil. Canceling their transformations, Emu and respectively introduced themselves before wishing each other luck in saving many patients and liberating the universe from Jark Matter before Emu was returned to his world.

Kamen Rider Heisei Generations FINAL: Build & Ex-Aid with Legend Riders
Emu eventually finds what he assumes to be Kamen Rider Build, asking him to return his powers back, Banjo, who is confused says that he does not know that what Emu is talking about.

Kamen Rider Build: Be The One
Among the first 18 Heisei Riders, Ex-Aid fought against numerous monsters in a melee briefly witnessed by Sento Kiryu, who recognized Ex-Aid, before being caught in the crossfire as Kamen Rider Zi-O BuildArmor used his Vortex Time Break to wipe out his enemies.

Personality
Emu Hojo is a very clumsy and yet a serious doctor to take on his job. However, his thirst for playing video games has a problem of Emu being absent-minded at times. An example of this is he sometimes fails to remember his work schedule properly and it makes the nurses scold him. He also has a habitual quirk of tumbling down in various comical ways.

As "M", his alias that he uses when playing video games, he shows a completely different side of himself. He displays a focused, calmer, and more confident demeanor. His grammatical persona also changes from 僕 into 俺, proving to be extremely skillful at video games, to the point where he has come to be known as the "genius gamer" who never leaves any game unfinished. This carries over to his battles as Ex-Aid, as his knowledge of video games has proven to be a definite advantage. Originally, when shifting to his Genius Gamer M personality, a wind blows through his hair and he makes a cocky smile. But during episode 10, Emu's eyes instead flash pink before turning a less intense, glowing red, after which, his eyes turn back to normal. Though he still makes the same cocky smile as before, showing that he can actually shift into his gamer persona at will. In the past, Emu's normal and "M" personalities were once one and the same, though following his surgery by the Next Genome surgeons, the leftover Bugster Virus in his body caused him to develop a case of, constantly switching from his naive side to his predative "M" persona. After learning that he was infected with the Bugster Virus, Emu's gamer persona took over as the dominant one, showing no concern for his patients and was instead only interested in playing the game, something which greatly angers Hiiro. However, after Hiiro states what it means to be a doctor, Emu regains control over himself, and becomes fearful of transforming into Ex-Aid. After he gains his resolve, he loses his fear of becoming Ex-Aid.

Emu has a very idealistic attitude towards being a doctor: he invests himself in the well-being of his patient, hoping to help them both physically and personally. He will always try to help a patient in need, even if they are a criminal, an enemy, or refuse to get help. For him, a life is a life and it's worth saving, fitting the morality of a true doctor and their devotion to the. This mindset helped him connect stress as a catalyst for Bugster infection, but also hinders him if the enemy is smart enough to threaten the patient's life. His firm idealism has led to clashes with his fellow CR Rider, Hiiro. Hiiro views Emu as naive and inexperienced, while Emu openly opposes Hiiro's detached and callous approach, going as far to say Hiiro is not a real doctor.

However, Emu is not without a dark side. When pushed too far, Emu can lose control of his temper and when that happens his Gamer side becomes as vicious and selfish as his rivals. This was shown when Kyotaro is infected by Graphite. Emu become so frustrated into believing that he's the only one who can save Kyotaro, to the point that he'll do anything to capture the Hunter Gamer using a stolen Gashacon Sword. While this shows that Emu takes pride in his beliefs as a doctor, at the same time it demonstrates that as a Gamer he shares Genm's and even Taiga's ideals to some extent. However, after some enlightenment from his idol, Kyotaro Hinata, Emu decides to trust his fellow doctor Riders, while also gaining respect from them over time.

Often after transforming, he says his catchphrase I'll clear this with No Continues! (ノーコンティニューでクリアしてやるぜ).

Family

 * Kiyonaga Hojo - Father
 * Unnamed Mother (deceased, passed away due to illness)

Powers and Abilities

 * Game Proficiency: Emu is highly adept in the field of video gaming, both in creative concept and actual practice. As a kid, he often creates game ideas that even Kuroto Dan, a genius game developer, recognized and envied. As a Kamen Rider, his creative concepts in gaming had lead to the creation of Mighty Brothers XX and Maximum Mighty X Gashats and the Save Energy Item, all arsenals that counters all of his toughest adversaries, specifically Genm, Para-DX, and Cronus. In actual practice, even without the influence of his Bugster, Parado, and the gaming skill of his Genius Gamer M persona, Emu is already a masterful gamer on his own with gaming skills formidable enough to see through the loopholes and weaknesses of every game and figuring out the methods of clearing them. As Genius Gamer M, Emu's skills in gaming and his battle prowesses are greatly enhanced especially when he enters a state of emotional rage or frustration, as shown when he effectively, in separate occasions, outmaneuvered both Genm and Snipe who are both at their Level 3 forms while Emu is only on Level 2. Furthermore, if his Genius Gamer persona is 100% active, his gaming skills skyrocket to a frightening degree evidenced on how despite being only at Level 3 he managed to overpower Gatton Bugster who is a Level 30, stating that one of gaming's thrills is figuring out how to defeat stronger opponents.
 * High Interpersonal Skill: Despite his clumsiness, Emu's kindness has allowed him to connect with all of his patients. This also extends to other Riders, showing how his influence allow them to cooperate properly. It is also worth noting that during their battle against Cronus, the absence of Emu and his inability to transform resulted with their defeat and the confiscation of three Gamer Drivers.
 * Original Bugster Virus: Being a Patient Zero (along with Masamune Dan), Emu was host to the virus for a prolonged period of time. This allowed the virus to fuse with and alter his DNA granting him Rider and possibly even Bugster-like powers and abilities that, by standard, requires external intervention to acquire.
 * Natural Game Disease Immunity: Unlike the other Riders, but later like Masamune, Emu can utilize the Gamer Driver and Rider Gashats without the need of the compatibility surgery. Also, his immunity is absolute, unlike the other Riders' acquired immunity which can still be overwhelmed by a large dose of Bugster virus, as he was unaffected when using the Mighty Brothers XX Gashat for the first time.M is laughing.png
 * Game Disease Cancellation: According to Episode 29 and the fact that Parado doubles as Emu's natural immunity to the Bugster Virus, the Bugster Virus Origin and as the one who activated the Game Disease on him, when Emu's resolve is strengthened by any means (in this case, Parado harming his friends), he can make the Bugster Virus inside him his own by forcibly stopping the Game Disease Parado has started on him.
 * Gashat Creation: As Patient Zero of the Bugster Virus, the progenitor of all the Rider Gashats and Bugsters as stated by Hiiro, he can use the Bugster Virus in him in conjunction with certain blank Gashats to create new, stronger forms for himself. This causes the Bugster Virus in him to evolve and become even stronger, which made Emu as Ex-Aid become stronger in return. Emu demonstrated this ability twice so far in the series with the creation of Mighty Brothers XX and Maximum Mighty X. He can also modify Gashats to a degree, displayed when he used his Bugster Virus to modify the Proto Bakusou Bike Gashat into the Combi Fukkatsu version.
 * Dual Personalities: Due to the Bugster Virus in Emu's DNA, he has two different personalities, which can be separated when using Mighty Brothers XX. This became dormant after Emu reprogrammed Parado, but was reawakened after re-injecting Parado into his body.
 * Parado Respawning: A side effect of this trait, ever since Parado became the Double Action Gamer Level XX R. If Parado's physical existence is terminated while not letting him dissolve into data and absorbing his core, Emu can simply absorb his remnant data to cultivate and respawn him again.
 * Increased Physical Strength: In at least one occasion, the spontaneous activation of Emu's Bugster infection allows him to exert great physical strength without transforming.
 * Pause Bypass: The same infection is also used to single-handedly destroy Cronus' Buggle Driver II with a single punch whilst time was paused, thereby cancelling the ability, and lowering Cronus' power such that he could be taken down by four Level 2 riders.

Weaknesses

 * Parado (Formerly): Since Parado is the Bugster created from Emu, like most Bugsters, Parado can possess Emu and take over his consciousness with no effort. However, Parado can't possess Emu when he transforms into Ex-Aid Double Action Gamer Level XX (as they split into Level XX L and R), or when Parado is inside a Game Area created from a Level 0 Gashat (Proto Mighty Action X Origin). However, Parado begs Emu and saying to him for killing any people to be vanished or making a struggle against, he accepts him; which Emu is not inflicted by him, making his weakness never make him feared and now converts into friendly, connected bonds forever, resulting his Game Disease converted into his own "powers" and he became uninfected. At the same time, since gaining Hyper Muteki, Emu, as Ex-Aid, is literally invincible against any form of attack. However, since Muteki Gamer is accessible due to the fact that Emu has an incredible power of Genius Gamer M which enables him to manifest through the existence of Parado. If Parado is defeated, his power of Genius Gamer M and his ability to transform into Ex-Aid and to Muteki Gamer will be all gone; meaning that he's not able to use any Gashats anymore.
 * Soft-Heartedness: Due to Emu having an idealistic attitude towards being a doctor, he often lets his emotions take control of his body, rendering him unable to carry out what he/his comrades originally planned to fulfil. This is especially evident in his fight against Hiiro, as Hiiro managed to easily defeat Emu even though the level gap was so wide.

Taiko no Tatsujin
Ex-Aid appears as a costume of Don Wada in Taiko no Tatsujin, obtained by playing EXCITE.

Devices

 * Kamen Rider Ex-Aid
 * Gamer Driver - Transformation device.
 * Rider Gashat - Transformation trinkets.
 * Kimewaza Slot Holder - Carrier strap for the Rider Gashats.
 * Robot Gamer - Ex-Aid's Level 3 support robot summoned by the Gekitotsu Robots Gashat.
 * Burger Gamer - Ex-Aid's Level 4 support robot summoned by the Ju Ju Burger Gashat.
 * Hunter Gamer - Ex-Aid's Level 5 support robot summoned by the Drago Knight Hunter Z Gashat.
 * Maximum Gamer - Ex-Aid's Level 99 support robot/armor summoned by the Maximum Mighty X Gashat.
 * Pac Gamer - Ex-Aid's support robot summoned by the Pac Adventure Gashat.
 * Game Scope - a stethoscope-like device used by CR to detect for the presence of the game illness among other uses.
 * Akarider
 * Typhoon - Transformation device.

Weapons

 * Gashacon Breaker - Standard sidearm weapon, can be a hammer or a sword.
 * Gashacon Sword - Brave's primary blade weapon that Ex-Aid borrows.
 * Gekitotsu Smasher - Robot Action Gamer Level 3's personal weapon.
 * Trick Flywheels - Sports Action Gamer Level 3's personal weapons.
 * Dragon Fang - Hunter Action Gamer Level 5 (Dragon Fang/Full Dragon)'s personal weapon.
 * Dragon Blade and Dragon Gun - Hunter Action Gamer Level 5 Full Dragon's personal weapon.
 * Gashacon Key Slasher - Double Action Gamer Level X(X), Maximum Gamer Level 99 and Muteki Gamer's personal weapon.
 * Daidaimaru - Gaim Gamer's personal weapon.
 * Handle-Ken - Drive Gamer's personal weapon.
 * stick pair - Accessed via the Taiko no Tatsujin Gashat.
 * Front/Rear Armed Unit - Bike Gamer Level 1's personal weapon; temporarily used by Bike Action Gamer Level 0 via the Proto Bakusou Bike Gashat (Combi Revival ver.)

Vehicles

 * Kamen Rider Lazer Bike Gamer Level 2/Bike Gamer - Lazer's Rider Machine Mode that Ex-Aid can use to ride. Until his death, shortly after a dying Lazer gave Ex-Aid his Gamer Driver and Bakusou Bike Gashat for Ex-Aid's use as his personal Rider Machine.
 * Sports Gamer - Secondary Level 3 support robot/Rider Machine summoned by the Shakariki Sports Gashat. Formerly belonged to Kamen Rider Genm.

Legend Rider Devices
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Relationships

 * Seito University Hospital CR
 * Asuna Karino/Poppy Pippopapo/Kamen Rider Poppy: Asuna is a close ally for Emu and mostly acts as his main assistant nurse. Initially, He still called Asuna by that name even when it was Poppy. But after saving her from the brainwashing of Ren and Parado, he began to always call her by her real name: Poppy (considering how he called her at first, that shows that their relationship has become much larger over time). When Ren Amagasaki (Lovelica Bugster) brainwashed her (And later Parado revealed that her Memory was erased), Emu was the most worried. He was the only one who still had faith in saving her, noticing her smile when Taiga and Nico reconciled. When Hiiro, Taiga and Nico attacked her in their attempt to complete Kamen Rider Chronicle, Emu was the one who stopped them, shouting that she was not their enemy (This is the only time that Emu's priority has not been his patients, except when he was controlled by Parado). He decided to save her even when he did not know how to cure his patient without defeating her and even shouted "Shut up" to Hiiro when he said that they should kill her for the sake of his patients). Until she told him she did not want to hurt anyone, that she wanted to get along with everyone, Emu replied "Let's play together", making her smile, achieving the "Game Clear", saving her. She hugged him and thanked him, furthermore, she was the first to worry when Parado seized his body and became determined to return Emu's smile at all cost. When Poppy chose to sacrifice herself to cure the rampant Gamedeus virus from infecting the public, Emu was heartbroken as they didn't fulfill their promise. But he was overjoyed when Kuroto managed to bring her back.
 * Hiiro Kagami/Kamen Rider Brave: Emu and Hiiro develop a rivalry relationship as both have polar opposite ways on taking care of patients. Hiiro also becomes the second reason why Emu decided to not quit fighting as Ex-Aid. Hiiro in return sees Emu with animosity and sees his presence as an Intern and a No Thank You. However, Emu indirectly helped Hiiro to regain his confidence in his skill as Genius surgeon, while Hiiro also acts as a senior to Emu, once helping him to escape from Genm Zombie Gamer Level X's Critical Dead (but he still takes Emu's Gashats away as punishment). Emu also appears to have gained some respect for Hiiro when he agreed to help perform cancer surgery on a patient while he was curing the same patient's game disease. In return for being reminded of Saki's final wish after Kuroto's death at the hands of Parado, Hiiro gives a warmful lecture that losing someone and failure are also part of doctors' life to move on. When Hiiro began to work Masamune Dan, Emu disheartened by his decision and couldn't fight him seriously. But, because it's revealed that it was Hiiro's chance to bring Saki back, he began to feel more sympathetic towards him. He then decided not hold back on him, regardless. When Taiga was critically injured by Parado and Graphite, Hiiro was responsible for his emergency surgery. Emu believed in Hiiro's efforts to save Taiga, even disregarding Nico's warnings and confronting Masamune Dan about it. After Hiiro saved Taiga and realigned himself with CR, his relationship with him went back to normal.
 * Haima Kagami: Haima is a senior for Emu. Although Emu respects him, Haima initially acts tough towards him, although this is only a coy.
 * Taiga Hanaya/Kamen Rider Snipe: Emu and Taiga also developed a rivalry. However, Taiga is the only doctor that Emu won't get close into unless they encounter the same problem. Taiga also seems to despise Emu, although he does call him by his title, Genius Gamer. Taiga is one of the first to discover that Emu has game disease. After Kamen Rider Chronicle had started, although still keeping an arrogant persona, Taiga shows some level of respect for him.
 * Kiriya Kujo/Kamen Rider Lazer: Emu was initially reluctant to get close to Kiriya. But ironically, Emu is the only one who believes Kiriya despite the many lies he'd given to him, which was for Emu's own benefit. Emu eventually felt that he got to understand Kiriya, but due to his death, Emu became enraged towards Kuroto. Even when Parado kills Kuroto, which indirectly helped Emu to avenge Kiriya's death, Emu still feels that avenging the fallen victims by killing the true suspect doesn't seem right. Their partnership also shown to be the best, shown when Kiriya was ressurected as a Bugster, the two began to be at odds with each other, due to their stand on opposing sides. When there was a chance, Kiriya whispered Emu "to lie" which Emu understood and they managed to pull act, succeeding in defeating Cronus for the first time with Muteki Gashat. The two resume their friendly relationship with one another.
 * Genm Corp.
 * Kuroto Dan/Kamen Rider Genm: When Emu was a child, he was a fan of the games that Kuroto had developed. Even as Emu joined CR later as an adult, he still had great trust in Kuroto, unaware that Kuroto was his nemesis Genm, right until Kuroto reveals his true motives of collecting data to complete the ultimate game. Emu's hostility towards Kuroto later deepens once he learns that Kuroto had killed Kiriya. However, even after all the sins that Kuroto has committed, Emu feels that killing Kuroto would not seem right as he would rather have Kuroto live to repay for the evil deeds he has done. This is especially shown when Emu decides to take Kuroto into CR when Kuroto was infected with the Bugster virus, even when Kuroto was already apprehended by the Ministry of Health. After seeing Kuroto suffer his tragic Game Over, Emu would later cry for Kuroto while alone. Eventually he no longer has remorse towards Kuroto anymore when both meet again in Kuroto's impossible game world for his resurrection to continue his ambition, just as Parado warned Emu before, whether dead or alive, Kuroto has always been a complete monster whom never knows when to quit his evil ambition towards humans and Bugsters alike. When Kuroto is later revived, though Emu does not forgive him, he gives Kuroto the chance to make up for his sins. Because of his cooperation with CR in defeating Kamen Rider Chronicle, Emu began to slowly trust him again, even in pivotal fights.
 * Graphite: Emu has been seen as Graphite's number one nemesis as Emu is the only Kamen Rider who is able to take care of most Bugsters easily. Especially, when Graphite infects his idol, Kyotaro Hinata. Ultimately, Emu destroyed Graphite with the help of his fellow Doctor Riders.
 * Parado/Kamen Rider Para-DX: Parado took an interest in Emu. He at first mocked Emu that life is like a game and once humans die, it's game over for them (they can't come back). However, upon seeing Emu's determination to save lives, Parado gives him a blank Gashat, wanting to observe his fate. After Emu created the Mighty Brothers XX Gashat, Parado said that Emu is really exciting. Parado starts insisting on fighting with Emu after Kamen Rider Chronicle had started, but Emu ignored him since he was more focused on saving people. Having become fed up with Emu's Hippocratic Oath preventing their fight, Parado reveals that he's actually Emu's 'M' Personality and also his manifested Bugster all along. Regardless of the connection between each other, Emu hates Parado because of how he is willing to take lives, Bugster and humans alike. When suggesting they should team up, he would always refuse. Emu however depends on Parado's continued existence because as long as Parado remains alive, Emu retains his ability to transform into Ex-aid and utilise Hyper Muteki. After their final confrontation, that leads to Parado's supposed death, Emu made him understand the value of losing a life which leads to begging forgiveness to the former for all the lives he took, Emu struggling to forgive him have finally accepted Parado as a part of himself. Each others made the promise to fight together for protecting lives, but at the same occasion Emu swore to Parado, that they will make up for his sins together. After their reconcilliation,it is shown that when they fight together against Cronus, Poppy notes that their "Hearts are connected", which proves to be correct to the way that both have a genuine care for the other's safety. Emu was devestated when Parado chose to sacrifice himself to destroy Gamedeus. But he was very relieved to see a part of the Game Virus was in Emu, allowing Parado to survive.
 * Masamune Dan/Kamen Rider Cronus: Emu and Masamune have met each other through unknown means since 2000 and during Emu's special surgery led by Kyotaro when Emu was a patient zero. Once Emu learned that Masamune was framed by Kuroto for a Zero Day back in 2011, Kiriya's death, and Kuroto spills Emu's secret being a patient zero, Emu wants to know more from Masamune and promises to put Kuroto in custody. While avenging Masamune's reputation, Emu failed to arrest Kuroto when Parado kills him. Following Kuroto's revival as Bugster, he now has to work alongside him to limit the continuing damage of both Parado's actions and Kamen Rider Chronicle's infections to further protect Masamune's reputation. However, it was revealed that Masamune was orchestrating events to eventually become Kamen Rider Cronus, revealing his true, villainous personality. Masamune is also the 'other' Patient Zero of the Bugster virus, thus allowing Masamune to use Gashats to transform. Emu is willing to stop Chronicle at all costs, even going to talk Masamune out of it. After that failed, he is willing to stop Cronus by force.
 * Ministry of Health
 * Kyotaro Hinata : Emu highly respects Kyotaro, to the point of debt-like respect because Kyotaro was the one who saved his life 16 years ago. In return, Kyotaro helps Emu by giving him some advice regarding his Doctor idealism.
 * Others:
 * Takeru Tenkuji/Kamen Rider Ghost: Due to his similar Rider Form, Emu was falsely marked as an enemy due to Genm's attack on Makoto and Alain. This was resolved and they bonded quickly, as they share the same philosophy of protecting all life. During Heisei Generations, they even show how far they will go to protect each other.
 * Shinnosuke Tomari/Kamen Rider Drive: First met in Heisei Generations, they share a bond to be the best Rider they can be to protect the world.
 * Haruto Soma/Kamen Rider Wizard: First met in Heisei Generations, Haruto almost mistaken as an enemy when he joined the Next Genome Institute. But Haruto explained that he only did so to attack them when they lowered their guard. He also shared a bond to be the best Rider he can be to protect the world.
 * Kouta Kazuraba/Kamen Rider Gaim: First met in Heisei Generations, they share bond to be the best Rider they can be to protect the world.
 * Team Ex-Aid: The team made in Chou Super Hero Taisen. Emu with his team also later become a temporary Super Sentai, Kamen Sentai Gorider and the leader.
 * Kaito Kumon/Kamen Rider Baron:
 * Kaoru Kino/Another Agito:
 * Yoko Minato/Kamen Rider Malika:
 * Kazuma Kenzaki/Kamen Rider Blade:
 * Sento Kiryu/Kamen Rider Build:
 * Ryuga Banjo/Kamen Rider Cross-Z: In Heisei Generations FINAL, Ryuga is sent to the World of Ex-Aid after Kaisei Mogami sent him via the Enigma portal. He later meets the Doctor Riders as well as Emu Hojo. Emu later confuses Ryuga as Kamen Rider Build due to wearing them wearing same driver. They both come across fellow riders, Eiji Hino and Gentaro Kisaragi.

Portrayal
Emu Hojo is portrayed by Hiroki Iijima (飯島 寛騎). As a child, Emu is portrayed by Rai Takahashi (髙橋 來). As Kamen Rider Ex-Aid, his suit actor is Satoshi Fujita (藤田 慧) in Level 1 & X, Seiji Takaiwa (高岩 成二) in Level 2, 3, 5 & XX R, and Jun Watanabe (渡辺 淳) in Level XX L. His sub for Level XX L is Takuma Komori (小森 拓真). When Level XX R is possessed by Parado, he is voiced by Shouma Kai (甲斐 翔真).

Rider No.
As the leading rider protagonist of Kamen Rider Ex-Aid, Ex-Aid is labelled Kamen Rider #33 (仮面ライダー33号) and Heisei Rider #18 (平成ライダー18号).

Etymology
Emu's last name, Hojo, is a pun on the Japanese word for "assistance" (補助), reflecting his job as a doctor. His first name may possibly be derived from the word "emulator", the meaning of which is made clear when the connection between him and Parado is revealed, as Emu serves as the "emulator" for Parado through the Genius Gamer M personality.

The name "Hojo" was also inspired by Karen Hojo, a character from the Idolm@ster series of rhythm/simulation video games, though Karen's surname is written with different Kanji. This reference was apparently slipped into the series by head writer Yuya Takahashi, himself an Idolm@ster fan. Emu's first name is a homonym of M, which is his name of Genius Gamer identity.

The name Ex-Aid is a portmanteau word from Extreme and Aid. The "Ex" in the name as well as the "X" in "Mighty Action X", may also be in reference to Kamen Rider X. Coincidentally when he returned in Kamen Rider Taisen, Keisuke Jin (X-Rider) had eventually taken a civilian job as a doctor.

According to Kamen Rider Build in True Ending, he describes Emu as a person who goes through extreme lengths to provide aid to his patients or in short, "Extreme-Aid".

Design/Video Game References

 * Kamen Rider Ex-Aid's design pays homage to typical fighter game characters such as from .
 * The gold "V" that Emu gains on his head as Ex-Aid Level 3 causes his face to resemble and could be a reference to the Gundam series, another popular series in Japan.
 * The design of Ex-Aid Maximum Gamer Level 99 echoes the Robobot Armor introduced in Kirby: Planet Robobot, as both involve the main character piloting a robot mecha enhancement which bears a variation of the main character's facial design on the chest.
 * True to its "Level 99" label, Ex-Aid's Maximum Gamer form has ability perimeters which are all related to the number "99", with the obvious exception of his height and weight.
 * Maximum Gamer's height and weight are instead likely a reference to the hexadecimal numbering system utilized by many 8- and 16-bit video games of the 90s. The maximum decimal value of a two-digit hexadecimal number is 255 (FF in hexadecimal); oftentimes, games started hexadecimal counts at 1 instead of 0 (as no value of 0 was expected for the given field), leading to the maximum value of any given stat being 256.
 * Similar to Maximum Gamer's relation to the number 99, the ability perimeters of Muteki Gamer are all related to the number "128". This number is the maximum life points can be reached in first Super Mario Bros., also the largest value of 8-bit in binary.
 * The ability perimeters of Pac Action Gamer, alongside with Famista and Xevious, are playing a Goroawase pun of Namco: 7 (ナ), 6 (ム), 5 (ゴ), and 5 is pronounced as voiced sound of Ko (コ).
 * Due to his primary Action Gamer forms/armors are related to Mighty Action X's inspirations, Ex-Aid's storyline, background and forms/armors are almost identical to Mega Man X and some of this game's protagonists.
 * Ex-Aid is the main protagonist of his series who has a hidden power from within and multiple forms/armors like X, and was the first progenitor of the earlier viruses like Zero.
 * During a live event, Emu's actor Hiroki Iijima revealed that early in development, Emu had a kind-hearted older sister who died young due to contracting the Bugster Virus from Emu, which would have motivated him to become a doctor. However, the character was written out because her backstory (a sickly girl who dreams of becoming an idol singer) was clearly inspired by Karen Hojo from the Idolm@ster game series.
 * Ex-Aid's transformation into Muteki Gamer after jumping out of the Maximum Gamer appears to be very reminiscent of Saint Seiya and Super Sonic transformations.
 * Muteki Gamer's gold color scheme and rainbow-colored eyes could be a reference to how certain characters become either gold or rainbow colored when invincible. Like how Sonic turns gold as Super Sonic, and Mario starts flashing multiple colors or is rainbow colored when he becomes Invincible Mario or Rainbow Mario respectively as some examples.