Emu Hojo

Emu Hojo (宝生 永夢) is one of the main characters and the main protagonist of Kamen Rider Ex-Aid. He is a trainee in pediatrics working at Seito University Hospital and a genius video gamer who goes by the alias M. He was given a Gamer Driver and the Mighty Action X Gashat by Asuna Karino to become Kamen Rider Ex-Aid (仮面ライダーエグゼイド) and destroy the Bugster viruses, to save his patient's life.

Past
When he was only eight years old, Emu was involved in an accident, leaving him critically injured. After receiving an emergency surgery, Emu was given a WonderSwan handheld video game device by one of the doctors as a reward for hanging on. This event would inspire Emu to become a doctor and help children like the one who saved him, Kyotaro Hinata.

During his childhood, he created the concept of the Mighty Brothers XX, stating that he does as such to lessen the burden of being alone.

Emu would later on win numerous gaming tournaments under the gaming alias of M, earning the interest of Asuna Karino as a potential candidate for using the Gamer Driver.

Becoming Kamen Rider Ex-Aid
Emu went on to become a pediatrics intern at Seito University Hospital. One of his patients, Sota Suyama, refused to be treated for his unknown illness and attempted to escape. While trying to catch Sota, Emu ran into Asuna, who was bringing the Gamer Driver while searching for M. When Sota suddenly collapsed, Emu and Asuna noticed unusual lumps emerging from the boy's neck. Not explaining Sota's condition to Emu, Asuna had the latter bring Sota with her to CR. Much to Emu's surprise, the hospital director Haima Kagami was there as well, ordering the intern to stay out. However, Emu disobeyed, hoping to make Sota feel better by bringing him to the release of the Mighty Action X game. Asuna ran into Emu and Sota at the game (believing that M would be at the press release), much to her frustration. However, when she tried to bring Sota back, he suddenly howled in pain and transformed into a Golem-like monster. Emu finally got Asuna to explain Sota's condition: he was infected by Bugster a computer virus threatening humanity, which could only be stopped by someone capable of using the Gamer Driver and destroying the virus. Determined to save his patient, Emu took the driver (and the accompanying Mighty Action X Gashat) without permission. Much to Asuna's surprise, not only was Emu able to become a Kamen Rider and extract the Salty Bugster from Sota, but he was, in fact, the gamer she was looking for. After transforming into Level 2, Emu defeated the Bugster, saving Sota's life. After checking on the boy, Asuna finally allowed Emu to access CR, and revealed her identity as Kamen Rider navigator, Poppi Pipopapo. She christened Emu as Kamen Rider Ex-Aid, and stated that he must become the super doctor to save humanity from Bugster.

The Rival and Surgeon Doctor, Brave
Shortly after getting acquainted with CR and reaquainted with Haima Kagami, Emu met Hiiro Kagami, Haima's son and a genius surgeon, who was working at a prestigious American hospital before being called back to the fight the Bugster as Kamen Rider Brave. Hiiro wasted no time in patronizing and antagonizing Emu, saying the latter's presence was a "No thank you". This caused Emu to doubt his worth to CR. Emu's inexperience became apparent while handling the next patient, Rensuke Natori. Emu went to Level 2 immediately, not realizing he needed to be in Level 1 to extract the Bugster. The Aranbura Bugster was quickly extracted by Brave, but both Ex-Aid and Brave were attacked by the mysterious Kamen Rider Genm, allowing the Bugster to escape and leaving Rensuke in critical condition. Emu was bewildered and disgusted by Hiiro's callous approach to patients: seeing them as just things to fix, and was more concerned with eating cake than Rensuke's well-being.

Hoping to buy time by reducing Rensuke's stress, Emu went to Rensuke's ex-fiancé, Asami, to find out why she called off the wedding. Their discussion led them to the church planned for the ceremony, where they were attacked by the Bugster. Emu transformed into Ex-Aid Level 1, but the Aranbura Bugster threatened to kill Asami if he changed to Level 2. Ex-Aid and Asami were saved by Brave's interference, and the two Riders managed to defeat the Bugster (Brave finished off the Aranbura Bugster). Emu's actions helped Rensuke and Asami restore their engagement. The incident prompted Emu to stay in CR, as he wasn't willing to leave patients in the hands of a doctor who didn't care about them.

The License-less Doctor Rider, Snipe
Emu ran into a paradox with one of his patients: a boy named Yuki Kitami who, as the result of an operation, had an irrational fear of doctors.

Emu followed after Yuki when the latter tried escaping from the hospital. Soon after he cornered Yuki Emu realized that the boy was infected by Bugster. In an effort to remedy the situation, Emu took off his doctor's jacket and called Asuna for backup. However, a mysterious man in doctor's attire appeared, aggravating Yuki and causing the Bugster to take over his body. The man turned into Kamen Rider Snipe Level 1 and quickly extracted the Revol Bugster. Emu helped Yuki get to safety, running into Asuna along the way. Yuki's fear of doctors caused the Bugster to regenerate quickly. Emu transformed into Ex-Aid Level 1 in an unsuccessful attempt to stop Snipe, eventually retreating with Yuki and Asuna hoping to calm the boy down.

After getting Yuki to CR, Asuna and Kagami explained that the man who appeared was Taiga Hanaya, a former radiologist and the rider chosen for CR during Zero Day, the initial Bugster outbreak. Failing to convince Yuki that he was safe, Emu got Taiga's location from Poppi, hoping to at least reduce Yuki's stress by convincing Taiga to stay out of the way.

Taiga refused Emu's offer, explaining that he would do what he wanted and his desire to get all ten Gashats to destroy the Bugster. He then challenged Emu to a duel: whomever defeated Revol would get the others Gashat. Their discussion was interrupted by the Bugster viruses attacking them, but Emu agreed to the duel after he and Taiga transformed into Ex-Aid Level 2 and Snipe Level 2, respectively. The fight was interrupted by Brave, who attacked Snipe in an attempt to take his Gashat. Ex-Aid snapped them out of their fight after reminding them that Yuki's life was at stake.

Yuki's high stress only strengthened Revol further, draining Ex-Aid and Brave's Rider Gauges with a brutal artillery assault. Rather than de-transform like Brave, Ex-Aid put himself directly in the line of fire, risking getting a lethal Game Over in order to get through to Yuki. Using an Energy Item, he wiped out Revol's troops before seemingly taking out the Bugster. However, the game remained in progress: it was revealed that the real Revol had hidden itself before Snipe finished it off. Having lost the duel, Emu's Gashat was taken by Taiga. However, Emu was simply relieved that Yuki was safe.

The Pumped-Up Coroner, Lazer
Sometime after losing his Gashat, Emu was confronted by coroner Kiriya Kujo, who had brought a Bugster victim, Yoshitaka Nishiwaki, with him under the guise of the former being a patient (claiming to be six in the appointment). Much to Emu's shock, Kiriya offered to get his Gashat back. Calling Hiiro to perform the operation, Emu confirmed Nishiwaki's condition and attempted confronting the patient. Hiiro and Asuna arrived for the operation, followed quickly by Kiriya and Taiga, the latter coming under the pretext of a duel. Nishiwaki was quickly taken over by the Bugster, with Kiriya and Taiga turning into Kamen Riders Lazer Level 1 and Snipe Level 1 to extract it.

After the Motors Bugster was extracted from Nishiwaki, Hiiro transformed into Brave and attacked Snipe. Lazer took the opportunity to steal the Mighty Action X Gashat back for Emu and turned into his Level 2 form. Much to everyone's shock, Lazer's Level 2 form was a motorcycle. This explained why Kiriya reached out to Emu: Lazer needed a rider to reach his top speed. Much to Lazer's chagrin, Emu focused on getting Niskiwaki to safety first, allowing the Bugster to get away.

Once Nishiwaki was in CR, he explained that his sister Riko had been kidnapped by another Bugster. Emu promised to save both him and his sister before finding Kiriya. Kiriya offered his friendship to Emu, who accepted. Lazer and Emu challenged Motors to a race, and after a heated and close fight, the two were able to defeat Motors and save Riko. As soon as Riko was safe, Lazer threw off Ex-Aid and denounced his friendship, admitting that he was only after getting a sample of the Bugster due to his curiosity. Unfortunately for Lazer, Motors was destroyed by Genm, who promptly turned into Sports Action Gamer Level 3 to attack the other Riders, depleting their Rider Gauges with the Shakariki Critical Strike.

Team-Up with 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 Kamen Rider 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.

Becoming Robot Action Gamer Level 3
Emu running around the street, wailing because he's waking up late and that he'll late to work. Suddenly, a hooded man asks for his help, and Emu stumbles upon a pile of trash before coming to help. After Emu scans him using his special stethoscope, he is about to transform when Asuna and Hiiro arrive. They both warn him that his patient is actually a thief who stole all newly developed gashats (Gekitotsu Robots, DoReMiFa Beat, Giri Giri Chambara and Jet Combat). This shocks Emu, but regardless of that fact, Emu still wants to cure him. However, a sudden quarell with Hiiro allows him to escape. When the trio gave chase, a new Bugster arrives, with the Gekitotsu Robots Gashat installed on it's head. Emu and Hiiro transformed into Ex-Aid Level 2 and Brave Level 2 to fight the Bugster. However, the Bugster is powerful enough to deplete some of Ex-Aid and Brave's Rider Gauges. To make things even worse, Genm in Level 2 appeared and transformed into Sports Action Gamer Level 3 before beating Ex-Aid and Brave. Genm himself had vanished along with the Bugster. While Emu was busy searching the patient, Kiriya appeared and said that Genm's true identity is the patient himself.

Back at the CR, Emu meets Kuroto Dan and they exchange a rather warm welcome. Emu is still not wavering about his choice to save that patient, but Hiiro, sick of Emu's idealism, grabs him by the collar. Emu angrily states that Hiiro wasn't a doctor before he fled to a helipad. There, he was confronted by Dan again. Emu explains that he just can't let the patient become a Bugster. Dan compliments him that his heart is like a shining crystal, but once a malicious patient shatters it, the crystal won't able to shine again. Emu states that he'll save the patient anyway, since he'll regret if he even abandon his patient, before giving chase to the patient again.

At an Avenue, Emu confronts the Collabos Bugster. Suddenly, Hiiro, Taiga and Kiriya appeared. Taiga challenges them all to a game. Whoever claims the Gekitotsu Robots Gashat gets to keep it as a prize. However, Kiriya states that he has other business to tend to, as Genm appeared, already in Level 3. Hiiro, Taiga and Kiriya transformed into Brave Level 2, Snipe Level 2 and Lazer Level 1 to fight Genm and the Collabos Bugster. However, to make things even worse, the patient, using the Gashacon Bugvisor, transformed into the Graphite Bugster. An enraged Snipe attacks Graphite.

Without breaking a sweat, Genm & Collabos manage to deplete Brave and Lazer's Rider Gauges, effectively cancelling their transformation. Snipe also unable to defeat Graphite, also cancels his transformation. Genm then chokes Emu, provoking him. Genm states that Emu's idealism doesn't work on the real battlefield. For Genm, Might makes Right. This statement finally causes Emu to snap, transforming into Ex-Aid Level 2 out of rage.

Shortly, using Mighty Critical Finish, Emu destroys the Collabos Bugster and claims the Gekitotsu Robots Gashat. Using the newly acquired Gashat, Emu transforms into Robot Action Gamer Level 3 and finally beating Genm. However, Genm manages to flee, with Emu roaring in rage before cancelling his transformation.

Second encounter with Graphite and Hiiro's Past
Emu comes to Genm Office and hand Gekitotsu Robots Gashat back to Kuroto Dan. Dan politely refuse, and say that since Emu's the one who win the Gashat fair and square, he could keep the it. Emu thanked Dan before leaving to meet a victim of Robots Collabos attack. Uberknowst to him, Dan already record his Level 3 data for later use.

Emu and Asuna later seen at Kiyosora to meet the victim, Seiichi Kuboyama. Seiichi Girlfriend, Yoko ask for a Break in their relationship which Seiichi half halfheartedly agree before he left. Suddenly, Yoko fall down, already infected by Game disease after Emu checked her using his Special Stethoscope. Hiiro suddenly appeared and decide to operate Yoko, much to Emu chagrin. After Yoko turned into Bugster Union, Hiiro transformed into Brave Level 1 and quickly extract Yoko from the Bugster. Graphite, in his human form soon make his appearance and confront the doctor riders. He claims that he'd infect Yoko using two game viruses (Gekitotsu Robots & DoReMiFa Beat), and this prompt Emu to join the fray as Ex-Aid Level 1. Beat Collabos then attack Ex-Aid and Brave using Rhythm based attack. Ex-Aid manage to get a perfect, but Brave get a miss and Damaged in process. After Graphite assume his Bugster form, Ex-Aid changed into Robot Action Gamer Level 3, while Brave into Level 2. Snipe in Level 2 also comes not long after, but Graphite use Gekidoryuga and severely damaged Brave and Snipe (Although they do attempt a counter attack) while Ex-Aid is barely holding on. Before Ex-Aid and Graphite could battle any further, Genm Sports Action Gamer Level 3 appeared and order Graphite to retreat, which the latter begrudgingly agreed.

After they all cancel their transformation, Emu stop the quarrel between Hiiro and Taiga, also overheard about Hiiro late Girlfriend, Saki. After he and Asuna brought Yoko to CR to be quarantined, Emu heard from Haima and Asuna about Hiiro past five years ago. Then, Emu and Asuna goes to check Yoko again. Yoko Explained that Seiichi tried to join a famous orchestra, but always failed in every audition. That's why she want to keep her disease a secret, so that Seiichi could concentrate on his next audition. Suddenly, after he receive the bugster coordinate, Yoko become stressed and beg Emu to save Seiichi. Emu Promise that he'll save both Yoko and Seiichi before he left.

Shortly, Emu manage to confront Beat Collabos by transforming into Ex-Aid Robot Action Gamer Level 3, while Hiiro's still busy with his personal Vendetta against Graphite by transforming into Brave Level 2. As Graphite's about to finish Hiiro off, Ex-Aid jumped in front of him and took the damage, effectively cancelling his transformation. Emu then told Brave about Yoko current condition and relate Saki with Yoko, as he believe that Saki's keeping her Game disease a secret in order to let Hiiro continue his study without worry. Emu was later carried by Asuna as they witness Brave defeat Beat Collabos, acquire DoReMiFa Beat Gashat and use the new Gashat to change into Beat Quest Gamer Level 3 and defeat Graphite.

Kiriya Kujo's Dark Past and Reason for His Lies
Emu is shown in CR along with Asuna in quarantining the patient, Yoshio. There, as Hiiro joins and Yoshio turned into Ouroboros - like Bugster Union. Emu and Hiiro transformed into Ex-Aid Level 1 and Brave Level 1 to extract the bugster, and they do succeeded in doing so. However, like the previous patient, Yoshio had been infected by two game viruses. One is Giri Giri Chambara and the other one is Jet Combat. As Ex-Aid and Brave transformed into their Level 3 forms, Genm Sports Action Gamer Level 3 appeared and helped the Bugsters to escape.

As they returned, Kiriya appeared in CR. When asked why, Kiriya say that someone (Haima) dropped his files in front of CR's sliding door. But, having learned that Kiriya is a liar, Emu and co. took caution and decided to mind their own business, much to Kiriya's dismay.

Emu then tride to talk with Yoshio about his current condition. Unbeknownst to him, this made Yoshio 'fire' his only daughter, Shiori from his job. As Emu is astonished, Kiriya appeared and grabbed Emu by the collar. Kiriya stated that sometimes, lying is the best way to give bad news to people, as he was traumatized by being too honest years ago. He also explained that Yoshio used that lie to his daughter, to make her start anew. As Asuna reports that the Bugster is on the loose, Kiriya say that the Bugster is about to attack Shiori to increase Yoshio's stress, which turns out to be true.

Deciding to trust Kiriya once more, Emu and Kiriya transform into Ex-Aid Level 2 and Lazer Level 2 to fight with Chambara Collabos, while Hiiro as Brave Level 2 is busy against Genm Level 2. With the perfect conjunction of Lazer's speed and Bakusou Critical Finish, Ex-Aid gains the Giri Giri Chambara Gashat and immediately decides to use it on Lazer, effectively transforming him into Chambara Bike Gamer Level 3. Emu later witnesses that Genm is Parad (thanks for the latter plot). Having no other choice, Kiriya lied to Emu again that he helped Emu to get his hand on the Giri Giri Chambara Gashat. Heartbroken, Emu finally distrust Kiriya.

The Rematch with Taiga
Emu's still dispirited after Kiriya 'lying' to him again, before he decide to not let this incident to bother him, as Yoshio's still need to be saved. As Yoshio ask about his current condition, Emu tell him the truth and ask about another factor that stressed him out, Asuna then came and said that Yoshio factory progress is another stress factor to him, which Yoshio complies. Yoshio said that many employees are quitting and that's the sole reason Shiori decided to handle the job while he's gone. However, before Yoshio could talk more about it, the Game disease symptoms appeared again...

Later, Emu and Asuna meet the remaining employee of Yoshio's factory and also Witnessing Taiga, as Snipe Level 2 defeat Combat Collabos. However, instead of destroying the Bugster, Snipe targeted the Gashat using his Gashacon Magnum which made it to him, while the Bugster reverted into its Prime form, and challenged Emu again. Snipe taunts Emu that if he want to save Yoshio, Emu must defeat him tommorow at noon. If Emu lost, his and Hiiro's Gashat will be confiscated by him.

He and Hiiro went to the waiting Taiga saying that he commends them for not backing up, which Emu replies that he gets the wrong way and that he is there just to save the patient while Hiiro said that he's not qualified to be Kamen Rider. Taiga in return, said that he will be one to collect all 10 Gashats. Emu, Hiiro, and Taiga correspondingly transforms to Ex-Aid, Brave, and Snipe, all of them at Level 2 to fight.

to be added

Dr. Pac-Man vs. Ex-Aid & Ghost with Legend Rider
It is revealed in Heisei Generation film, that the Bugsters was actually born 16 years ago from the body samples of their very first victim and future Kamen Rider, Emu Hojo. Their birth from Emu's samples was the result of unrecorded experiments on Emu's body to breed stronger Bugsters before Emu obtains a Bugster antibody from Kyotaro Hinata's surgery on the young boy.

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 absentminded 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 throw 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.

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, although only Kiriya did believe in him so far.

Powers and Abilities

 * Skilled Gamer: Emu is a masterful gamer, particularly in terms of platform gaming. He has extensive knowledge of games in other genres, including Bang Bang Shooting and Bakusou Bike and can adapt easily when playing a new game. These skills are further enhanced 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 while Emu is only on Level 2.
 * High Interpersonal Skill: Despite his clumsiness, Emu's kindness has allowed him to connect with all of his patients.
 * Natural Game Disease Immunity: Unlike all other Riders who had undergone a compatibility surgery to be immune from the Game Disease and able to transform into a Kamen Rider, Emu is capable of utilizing the Rider System even without the intervention of said surgery and seems to be unaffected by Bugster infection agents. Kiriya discovered the real reason behind Emu's condition but was silenced by Genm before he can reveal the truth. This unusual immunity is also what enabled the creation of the Mighty Brothers XX Gashat, as the blank Double Gashat injects a massive amount of the Bugster Virus, which will normally kill a Rider when used in the Gamer Driver, even when the Rider has already been immune to the Game Disease. He was the first person to be infected with the Bugster Virus as a kid, and was experimented on by Dr. Pac-Man to develop the later, more recent version of the virus, which is why he has natural antibodies for the virus and such can use the Gamer Driver without the need for an immunization operation.

Devices

 * 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.
 * Hunter Gamer - Ex-Aid's Level 5 support robot.

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
 * Gashacon Key Slasher - Double Action Gamer Level X(X)'s personal weapon.
 * Daidaimaru - Gaim Gamer's personal weapon
 * Handle-Ken - Drive Gamer's personal weapon.

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.

Ghost Eyecon
This Eyecon makes an appearance in the finale of Kamen Rider Ghost and in Kamen Rider Heisei Generations: Dr. Pac-Man vs. Ex-Aid & Ghost with Legend Rider. This Eyecon allows Ghost to transform into Ex-Aid Damashii.

Relationships

 * Seito University Hospital CR
 * Asuna Karino/Poppy Pippopapo: Asuna is a close ally for Emu and mostly like his main assistant nurse. He stills calls Asuna by that name even when she is Poppi.
 * Hiiro Kagami: 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 for becoming Ex-Aid. Hiiro in return sees Emu with animosity and sees his presence as an Intern and a No Thank You.
 * 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: 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.
 * Kiriya Kujo: 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 when he realized that Kuroto stole Kiriya's weapon for his own use.
 * Genm Corp.
 * Kuroto Dan: Emu had great trust towards Kuroto, unaware that Kuroto is his nemesis, Genm, until he finally revealed himself once he gathered all battle data from the doctor Kamen Riders, as Emu and three other doctor Riders are too late to notice and stop Kuroto's scheme.
 * Graphite: Emu has been seen as Graphite's number one nemesis as Emu is the only Kamen Rider who is mostly able to take care of Bugsters easily.
 * Parad: Parad 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, Parad gives him a blank Gashat, wanting to observe his fate.
 * Ministry of Health
 * Kyotaro Hinata : Emu highly respects Kyotaro, to the point of debt-like respect. Because he's the one who saved his life 16 years ago. In return, Kyotaro helps Emu by giving him some advice regarding his Doctor idealism.

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.