Mitsuzane Kureshima

"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.

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 becomes the second Kamen Rider Zangetsu Shin (仮面ライダー斬月 真 [ザンゲツ シン]), succeeding his older brother Takatora.

Character History
After Kouta's near death encounter with Armored Rider Zangetsu forces him to quit, Mitsuzane goes to Drupers and 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.

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. 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.

He tries to kill Gaim until Bravo arrives, as his fighting style behind Zangetsu Shin's suit cannot be fooled by Oren, leaving Mitsuzane speechless when Gaim demands him to reveal his identity. However, he manages to escape from Gaim as he uses Dyudyuonshu as a shield to block his attack, so his identity is not revealed. With all of his plans to manipulate events and eliminate Kouta ending up in failure, Mitsuzane becomes much more insane than ever before.

Personality
He is a member of Team Gaim and Kouta sees him as his younger brother. He is 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 him being able to be himself while there.

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. Currently, only Sid, Yoko, Ryoma, Kaito, Oren, and Redyue know about Mitsuzane's inner darker personality. It is soon spotted by Oren's battle instincts while under the guise of Zangetsu Shin. As a result of failing to kill Kouta and failing to manipulate other people's lives, Mitsuzane has been driven into insanity.

Arms
Like with the other Armored Riders and New Generation Riders, Kamen Rider Ryugen/Zangetsu Shin's forms are called Arms (アームズ). As Ryugen, all of his Chinese Soldier-themed Arms' helmets share the suffix Men (面) as their title, while his visors are called Ryugan (龍眼).

Devices

 * Transformation devices:
 * Sengoku Driver - As Ryugen
 * Genesis Driver - As Zangetsu Shin
 * Arms Weapons:
 * Ryugen:
 * Budou Ryuhou - Ryugen Budou Arms' personal weapon
 * Kiwi Gekirin - Ryugen Kiwi Arms' personal weapons
 * Trigger Magnum - Ryugen Double Arms' personal weapon
 * Pine Iron - Ryugen Pine Arms' personal weapon
 * Banaspear - Ryugen Banana Arms' personal weapon
 * Melon Defender - Ryugen Melon Arms' personal weapon
 * Zangetsu Shin:
 * Sonic Arrow - Zangetsu Shin Melon Energy Arms' personal weapon
 * Lockseeds - Gives access to Ryugen/Zangetsu Shin's form changes, depending on which arm the lock is

Vehicles

 * Sakura Hurricane - Borrowed Rider Machine from Gaim
 * Rose Attacker - Ryugen's Rider Machine

List of Appearances

 * Kamen Rider Gaim
 * 1-31
 * 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).

As Kamen Rider Ryugen, 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!"
 * Joker - "Joker, Kirifuda, Sei-ya Ha!"
 * Meteor - "Hwacha, Ha-Ha-Ha!"