Mitsuzane Kureshima

"Pain... and sadness... will never disappear. That's why... I'd rather get hurt than let it happen to those dear to me. Isn't that right? Kouta?"

- Mitsuzane before transforming for the first time.

"In the end, I haven't won anything for myself. But at least for her... For Mai alone, I will give everything to protect her! I would even give up my life for that!"

- Mitsuzane before using the Yomotsuheguri Lockseed.

"It's true he was a hero. But...Kouta isn't here now. That's why we have to be the heroes!"

- Post-Helheim invasion redeemed Mitsuzane before transforming to fight Jam

Mitsuzane "Mitchy" Kureshima (呉島 "ミッチ" 光実) is Kamen Rider Ryugen (仮面ライダー龍玄 [リュウゲン]). He later became the second Kamen Rider Zangetsu Shin (仮面ライダー斬月 真 [ザンゲツ シン]), and for a short time he became Kamen Rider Ryugen Yomi (仮面ライダー龍玄・黄泉 [リュウゲン・ヨミ]). As the new Zangetsu Shin, he supposedly succeeded his older brother Takatora as a protector of humanity. However, his vision of protecting humanity are disillusioned, placing most of his failures on his best friend, Kouta Kazuraba, after the latter involves Mitsuzane's love interest, Mai Takatsukasa into the conspiracy about Yggdrasill and Helheim. Because of this, Mitsuzane becomes misguided, transitioning from the safety of humanity to multiple attempts to kill Kouta in order to keep him away from Mai.

Early Life
As a young child, Mitsuzane was raised by his older brother, Takatora Kureshima. Their parents were always overseas, so Takatora raised Mitsuzane alone. Since childhood, Takatora has pushed Mitsuzane's expectations of him, including, school work and work life.

Beat Riders Saga
After Kouta's near death encounter with Armored Rider Zangetsu forces him to quit, Mitsuzane convinces Sid to give him a Sengoku Driver. From there, Mitsuzane becomes Team Gaim's second Armored Rider, the Chinese warrior-themed Kamen Rider Ryugen. After learning that the white Armored Rider, Zangetsu, is his brother Takatora, Mitsuzane resolves to uncover the truth behind the Yggdrasill Corporation's ties to Helheim Forest.

Yggdrasill Saga
However, learning of Yuya's fate prior with the intention of keeping Kouta in the dark about it, Mitsuzane renounces his earlier intent to expose his family's company upon being shown the ruins within Helheim Forest. Supporting the Yggdrasill Corporation in secret, Mistuzane maintains his appearance as a Beat Rider, going his own way to protect Kouta and Mai. Though he answers to Ryoma Sengoku, Mitsuzane learns that the scientist and his group are acting on their own agenda. Like his brother, Takatora, Mitsuzane is smart and revealed to be quite a manipulator with a desire to make sure Mai would live in blissful ignorance.

Helheim & Over Lord Saga
"Kouta Kazuraba. He crossed the line he shouldn't have crossed. He's my enemy now, nothing more and nothing less."

- Mitsuzane explaining to Sid of his hatred toward Kouta.

While initially admiring Kouta for his earnestness, Mitsuzane gradually finds Kouta's ideals and methods disagreeable, eventually become disillusioned with his friend after he tells Mai everything of the Inves and Yggdrasill's conspiracy. Combined with being slapped by Mai after taking his frustrations on Kouta for making her sad, an unhinged Mitsuzane plots to get rid of Kouta within Helheim Forest, so much so that he is willing to attack Kouta when his friend lowers his guard and kill him.

His plot is foiled by the interference of Kaito who, despite not caring much about what is going on between Kouta and Mitsuzane, cannot stand such cowardly acts. Mitsuzane follows his brother and Ryoma's group into the forest intent on stopping the Over Lords, however, Takatora is ambushed by his own group and is thrown off a cliff. Mitsuzane ignores his brother's pleas to work with Kouta to save humanity and uses his brother's Genesis Driver to instigate betrayal to Kouta. However he is intercepted by Kaito.

Mitsuzane is not as physically strong as his brother, despite the power given by the Genesis Driver. Instead, Mitsuzane uses the increased power and resorts to cheap tactics to fight as shown using the debris and junk off the abandoned construction site to his advantage and then calling Inves when he can't win.

After escaping from an enraged Kachidoki Arms Gaim and Lemon Energy Arms Baron, he watches them from a safe distance as he turns off his transformation, revealing that he is now the new Zangetsu Shin.

At Drupers, Mitsuzane is surprised to hear that Mai agrees to work there for free. Yoko then enters and asks both him and Kouta to come to Yggdrasill. There together with Kaito they hear from Ryoma that Sid betrayed Yggdrasill to seek the Forbidden Fruit from the Over Lords. After planning to find Sid in a separate way, Ryugen discovers where Sid is hiding. Rather than being enemies, they ally together and plan to kill Kouta and Kaito as Mitsuzane sets a trap into calling Gaim in Jimber Peach Arms for help as Ryugen in safe distance, then as Zangetsu Shin before Gaim arrives to find him, attempting to attack Gaim. However, he is easily defeated by Gaim Jimber Lemon Arms until they were interrupted by Demushu, with four Riders in a battle royale for the Over Lord until Demushu's escape through a sudden appearance of a Crack, leading Gaim and Baron to follow while Sigurd and Zangetsu Shin-suited Mitsuzane are confronted by Redyue, who after a brief skirmish gives up and tells them to follow where the Forbidden Fruit is.

Already aware of Redyue's trap after she suddenly gave up herself, Mitsuzane knows that Redyue has been planning behind their back, as well as Rosyuo's, to obtain the Forbidden Fruit for her own, with Redyue taking an interest in his dark side after Sid left for the fruit in the possession of Rosyuo and got himself killed.

Redyue gives Mitsuzane Sid's hat, with Mitsuzane unaware that Redyue has seen his brother alive. He leads an Inves army with Redyue and other Over Lord class Inves as they enter the real world.

Forbidden Fruit Saga
"If you'd had the guts to make the tough decisions, you could have been the hero humanity needed. That's why I admired you. That's why I thought you deserved Mai! But you've been twisted by the lies you called "hope". Your sweet optimism blinds you to reality, and forces you to make stupid mistakes over and over. Hope is a dangerous disease, and a contagious one at that. And you Kouta... have been spreading it like a plague!"

- Mitsuzane revealing his darkside to Kouta for the first time.

As Zangetsu Shin, Mitsuzane attempts to kill Gaim, but his fighting style easily gives indication to Bravo that he's an imposter, prompting Kouta to go all out, defeating Mitsuzane and Dyudyuonshu. However, Mitsuzane uses Dyudyuonshu as a shield and escapes with Kouta now knowing that Zangetsu Shin is not Takatora. Mitsuzane, upon seeing the power of Kiwami Arms, being berated by Yoki Minato that he no longer has a home after all of his actions, and seeing Rosyuo's power, realizes that humanity has no chance against the Over Lords. Mitsuzane allies himself with Redyue to commence his plans of being the world's ruler alongside her.

Attempting to persuade his friends to join his side with the Over Lords, he is left astounded as they all shun him. When Mai also refuses to join Mitsuzane, he targets Kouta once more, considering Kouta a blight and that his sweet optimism and naiveté has robbed him of all his friends. Revealing himself to be Zangetsu Shin, he's stopped by Takatora. In a later confrontation the next day, Takatora reveals that Mitsuzane is the reflection of every mistake he made. Though Takatora easily overpowers Mitsuzane despite Mitsuzane possessing the Genesis Driver, which is said to be much stronger than the Sengoku Driver, Mitsuzane is able to defeat his brother when Takatora hesitates to deliver the finishing blow. In the aftermath of the fight, Takatora is flung into the ocean with the Zangetsu suit that was attached to him starts to disintegrate as his Sengoku Driver is damaged beyond repair.

Mitsuzane, despite well knowing that his brother is "dead", gets vivid hallucinations of his brother's "spirit", who serves to contrast Mitsuzane's actions and opinions, effectively becoming the voice of reason and argument to Mitsuzane's actions. After no longer finding the need to masquerade as his brother, Mitsuzane is able to fight with an unwaivering resolve, defeating the undefeated Kachidoki Arms single-handedly and even taking on both a Kiwami Arms Gaim and Lemon Energy Arms Baron alone without any assistance. Mitsuzane later gives Mai to Rosyuo to protect her from both the Beat Riders and Redyue.

In a deadlock against Baron, the two clash ideals about the individualism of Mai with Kaito iterating that she is strong on her own and Mitsuzane's view on her as someone who needs to be protected. When Ryoma leaks the location of Mai, he witnesses the extinction of the Over Lords and realizes that Rosyuo has given Mai the Golden Fruit, rushing back to the Team Gaim Garage. Ryoma also appears, taking her to the hospital with the assistance of Peko and Chucky. Here, Mitsuzane learns the true origins of Sagara and is given the Yomoutsuheguri Lockseed by Ryoma, stating that it's a prototype Lockseed that sucks his own life force and turns it into massive amounts of energy. Mitsuzane also fears for the safety of Mai, not wanting her to become a "monster" like Kouta has and upon realizing that he can no longer remember why all of this has happened to him, Takatora's "spirit" appears once more before Mitsuzane, telling him that everything that has happened is the result of Mitsuzane's actions, and that his life has no value or worth.

Going to the pier to confront Kouta, he tells Kouta that even though his life has no value, he will protect the person that matters the most to him. Visibly affected by the effects of the Lockseed, Kouta attempts to tell Mitsuzane to get rid of the Lockseed, but as Mitsuzane suffers, Kouta transforms into Kachidoki Arms and later into Kiwami Arms. As Mitsuzame attempts to finish Kouta, Gaim willing takes Ryugen Yomi attack getting impaled by him while Gaim snatches the Yomoutsuheguri Lockseed from Ryugen Yomi. Critically wounded, Kouta still forgives Mitsuzane from his mistakes and wanting him to forgive himself before Kouta collapse from his wound. Returning to the hospital, he was horrified to learn that rather than save her, Mai had died as a result of Ryoma removing the Forbidden Fruit from her body, learning that the Professor never had any intentions of trying to save her life. Confident in his victory, Ryoma revealed he had been using Mitsuzane all along to further his own goals, just like his brother before him. Furious, Mitsuzane prepares to fight, however Ryoma remotely disables his Genesis Driver and attacks him before the fruit erupts, revealing he had installed a kill switch in all the Genesis Drivers in case of emergency. As Ryoma attempts to kill Mitsuzane however, the Forbidden Fruit erupts and becomes the Woman of the Beginning, bidding farewell to him. Having now lost everybody close to him, Mitsuzane suffers a complete breakdown, eventually found by Yoko and Kaito sobbing non-stop beside Mai's corpse.

When Kaito and Yoko return, they witness Mitsuzane standing over a disappearing Mai. Once she's gone, everyone assumed she was dead, before DJ Sagara appears and tells them that she isn't dead, and that's she's only lost in time. She also had accepted her duty as the Woman of Beginning, as she would give the Golden Fruit to the selected person. Kaito runs off, hoping to settle things with Kouta.

Since losing everything, Mitsuzane still continues to grieve over the loss of Mai. Takatora reappears and taunts Mitsuzane once again as Mitsuzane already gets it of what he has done into repeating his older brother's mistakes.

3 months after the fated battle between Kouta and Kaito won by Kouta into moving the Helheim plants and the Inves to a deserted planet as the world is finally saved but Kouta and Mai moved to their Inves Planet. Mitsuzane went hiding from the public. He found his unconscious brother before the last 3 months somewhere out of the river. He temporarily watches the Beat Riders dance, still remorseful of his sins. While leaving, he is soon spotted by Zack who forgives him. Mitsuzane leaves to the hospital to check up on his brother. When Takatora finally woke up, it brought Mitsuzane to tears.

Four months later (Seven months after Helheim left Earth), Mitsuzane is still unable to forgive himself as he reminisces his past friendship with Kouta. He lived the rest of his days bridging the bond with his brother, while keeping himself  isolated with eveyone else, including his Beat Rider teammates. When the Grasshopper Monster and Kougane attacks. Mitsuzane does not recognize Kougane because he has possessed a human girl and that Lapis had made all of those who participated in his Soccer World into a dream. As the only Armored Rider left on Zawame after Jounouchi's defeat, Mitsuzane takes on the Grasshopper Monster and Kougane, easily defeating the two of them. However, Mitsuzane is brought to his knees when Kougane uses his human host as a hostage. However, Kouta appears, forcing Kougane out of the female and the two destroy Kougane once and for all with a Burai Kick-Ryugen Kyaku Combo. After Kougane's defeat, Mitsuzane is having a brief reconcilation talk with Kouta before he left. Kouta assures Mitsuzane they will always be friends, and he reunites with his brother and his former Armored Riders comrades.

The Golden Fruit Cup Event
Set sometime after Ryoma Sengoku presents to Kouta a way to enter the Yggdrasill Tower through a back entrance, Mitsuzane's tragic memory of defeating Takatora is kept after the world is transitioned through the Soccer World, prompting him to realize that the current world he's in is fake. He acts alone for most of the film. When Kouta is brainwashed by Kougane, Mitsuzane steps up to snap him out of it, with the help of Lapis. The Riders gather to stop Kougane once and for all. However, Kougane survives his encounter and returns to the real world seven months later.

Personality
He was initially a member of Team Gaim and Kouta sees him as his younger brother. He was the son of a director of the Yggdrasill Corporation and attends an elite high school, a side of him which he keeps hidden from everyone. Living under his brother's shadow, he wants to live freely and break free from the path established for him, as such he sees Team Gaim as family due to him being able to be himself while there once.

He also respected Kouta once as a role model in the early stages of the show, basing his own beliefs around Kouta's and always want to do more to help others. He also harbors a secret crush on Mai, which drives him to ask for a Sengoku Driver from Sid and become a rider himself when Mai is at wit's end due to Kouta being shaken to the core after the encounter with Zangetsu. After knowing that Yuya Sumii turned into Byakko Inves and for Kouta as Gaim unknowingly killed him, Mitsuzane tried to hide this from Kouta and even Team Gaim, trying not to disappoint his friends.

Despite having a cheerful and optimistic personality, in reality, Mitsuzane also has a dark personality. He will use his own status or a current situation for his own benefit and sake. As shown, he convinced Sid to give him the Sengoku Driver, which Mitsuzane tells Sid that one day he will surpass his brother. Mitsuzane also forced Sid to give him a Lockvehicle or else Mitsuzane would tell Takatora that Sid is the one who gave Kouta the Suika Lockseed. Mitsuzane also stole the Suika Lockseed from his brother without any guilt and swears to betray anyone or everything as long he can retain his friends' happiness. He also tries to destroy Kouta after he learned that Mai likes Kouta more than himself. A majority of Yggdrasill know about Mitsuzane's inner darker personality. Alongside this, Kaito and Redyue are also aware of this sinister personality. As a result of failing to kill Kouta and attempting to manipulate other people's lives, Mitsuzane has been driven into insanity blaming Kouta for ruining his perfect image of the world.

Upon witnessing Rosyuo's power when he destroyed the missiles that were launched by the government, he becomes even more insane, believing that he has made the right choice in siding with the Over Lords. His mindset is that when the human race is destroyed, he would finally be able to do whatever he wants without anyone getting in his way, such as leaving Mai to live. His dark nature was then finally exposed to the Beat Riders resistance and later Takatora and Kouta.

In his battle as Zangetsu Shin, Mitsuzane was seen able to use almost anything in his advantage, for example throwing garbages and other objects (eg. sands for smokescreen) to keep the opponent busy, summoning Inves when outmatched similar to Kaito in his days as a Beat Rider, killing his own ally as an escape and even taking advantage of the opponents' weakness (eg. Kouta's naiveté and Takatora's empathy for him).

Because of Ryoma's influence on his brother, this caused the influences that Takatora was manipulated by Ryoma to affect Mitsuzane, leading him to ally with Sid (even though he betrays Ryoma, after betraying Takatora), Ryoma himself, and the Over Lords, turn him into a tragic villain and dumb enough into following a dark path. As the result of Ryoma's manipulation on Takatora that affects Mitsuzane, he ended up losing everything else after what he did in betraying humanity allying with most of the villains for nothing but his own dark purpose, causing him becoming a broken person.

Arms
Like with the other Armored Riders and New Generation Riders, Kamen Rider Ryugen/Ryugen Yomi/Zangetsu Shin's forms are called Arms (アームズ). His personal Lockseeds are styled either dividing into three parts or ending with a fighting grunt ("Ha-Ha-Ha" or "Sei-ya Ha"). As Ryugen, all of Mitsuzane's Chinese Soldier-themed Arms' helmets share the suffix Men (面) as their title, while his visors are called Ryugan (龍眼).

As Armored Rider Ryugen/Ryugen Yomi, Mitsuzane's Sengoku Driver plays Chinese erhu & gong music and announces "Hai" (ハイー) before every transformation. By pressing the Sengoku Driver's Cutting Blade down on the Lockseed after transforming from one to three times, he can activate one of three finishing moves based on his current Arms form: Squash (スカッシュ), Au Lait (オーレ), or Sparking (スパーキング).

As New Generation Rider Zangetsu Shin, Mitsuzane's Genesis Driver announces "Soda" (ソーダ) before every transformation. By pushing the Genesis Driver's Seaboll Compressor into the Energy Lockseed after transforming from one to two times, he can activate one of two finishing moves based on his current Arms form: Squash (スカッシュ) or Sparking (スパーキング).

Devices

 * Transformation devices:
 * Sengoku Driver - As Ryugen/Ryugen Yomi
 * Genesis Driver - As Zangetsu Shin (disabled by Professor Ryoma's self-destruct fail-safe)
 * Lockseeds - Gives access to Ryugen/Ryugen Yomi/Zangetsu Shin's Arms changes, depending on which lock is used

Weapons

 * Arms Weapons - Weapons that come with the Arms:
 * Ryugen:
 * Budou Ryuhou - Ryugen Budou Arms' personal weapon
 * Kiwi Gekirin - Ryugen Kiwi Arms' personal weapons
 * Melon Defender - Ryugen Melon Arms' personal weapon
 * Banaspear - Ryugen Banana Arms' personal weapon
 * Pine Iron - Ryugen Pine Arms' personal weapon
 * Trigger Magnum - Ryugen Double Arms' personal weapon
 * Faiz Edge - Ryugen Faiz Arms' personal weapon
 * Rocket Module - Ryugen Fourze Arms' personal weapon
 * Ryugen Yomi:
 * Budou Ryuhou - One of Ryugen Yomi Yomotsuheguri Arms' personal weapons
 * Kiwi Gekirin - One of Ryugen Yomi Yomotsuheguri Arms' personal weapons
 * Redyue's halberd - One of Ryugen Yomi Yomotsuheguri Arms' personal weapons
 * Shinmugurun's axe - One of Ryugen Yomi Yomotsuheguri Arms' personal weapons
 * Zangetsu Shin:
 * Sonic Arrow - Zangetsu Shin Melon Energy Arms' personal weapon
 * Storm Halberd - One of Zangetsu Shin Agito Arms' personal weapons
 * Flame Saber - One of Zangetsu Shin Agito Arms' personal weapons

Vehicles

 * Lock Vehicles - Vehicles that unfold from special Lockseeds:
 * Sakura Hurricane - Borrowed Rider Machine from Gaim
 * Rose Attacker - Ryugen's Rider Machine

List of Appearances

 * Kamen Rider Gaim
 * 1-36, 38-47
 * Kamen Rider × Kamen Rider Gaim & Wizard: The Fateful Sengoku Movie Battle
 * Kamen Rider Gaim: Sengoku Battle Royale
 * Sengoku Movie Battle
 * Heisei Rider vs. Showa Rider: Kamen Rider Taisen feat. Super Sentai
 * Ressha Sentai ToQger Vs. Kamen Rider Gaim Spring Vacation Combining Special
 * Kamen Rider Gaim the Movie: The Great Soccer Match! The Golden Fruit Cup!

Portrayal
Mitsuzane Kureshima is portrayed by Mahiro Takasugi (高杉 真宙). He was also a guest star in Episode 10 of .

His suit actor is Daisuke Satō (佐藤 太輔), who was previously the suit actor for Gokai Silver in Kaizoku Sentai Gokaiger and Beet J Stag/Stag Buster in Tokumei Sentai Go-Busters.

Legend Rider Lockseeds

 * The following Legend Rider Lockseeds are styled for Ryugen:
 * V3 - "Chikara, Waza, Double Typhoon!"
 * Skyrider - "Sky, Henshin, Sail-ing Jump!"
 * Super-1 - "Seki, Shin, Sho-rin Ken!"
 * Kuuga - "Chō Henshin, Ha-Ha-Ha!"
 * Double - "Cyclone, Joker, Ha-Ha-Ha!"
 * Double CycloneJokerXtreme - "Cyclone, Joker, Xtreme!"
 * Joker - "Joker, Kirifuda, Sei-ya Ha!"
 * Meteor - "Hwacha, Ha-Ha-Ha!"
 * Ryugen - "Bu-dou, Ha-Ha-Ha!"