Mutsuki Sano

Mutsuki Sano (佐野睦月) is a 17 year-old boy who has been trapped in Helheim for 13 years due to accidentally entering a Helheim crack. He finds the Sengoku Driver and Orange and Pine Lockseeds to transform into Gaim and escape Helheim.

Arms
Like his fellow Lockseed-using Armored Riders, Kamen Rider Gaim's forms are called Arms (アームズ). His Sengoku Driver plays Japanese horagai music and announces "Soiya" (ソイヤ) before every transformation, except when he transforms into Kiwami Arms, while his personal Lockseeds are styled with a mix of Japanese words and English words. With the exception of Suika Arms, all of Gaim's Japanese Samurai, Ninja and Shogun-themed Arms' helmets share the title Kabuto (カブト), while his visors are called Pulp Eye (パルプアイ).

By pressing the Sengoku Driver's Cutting Blade down on the Lockseed after transforming from one to three times, Gaim 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). In addition to the Sengoku Driver's finishing moves, Gaim can perform either a Fruits Charge (フルーツチャージ) or Sonic Volley (ソニックボレー) finishing attack by inserting a Lockseed into the attachment slot of either his Musou Saber, Sonic Arrow, or DJ Gun.

Byakko Inves= Byakko Inves In a dream placed by Redyue, Kouta had his role with Yuya Sumii reversed, causing him to become the Byakko Inves (ビャッコインベス) and Yuya to become Kamen Rider Gaim. Kouta eventually managed to escape and fight Redyue.
 * Height: 230 cm.
 * Weight: 157 kg.

This form is exclusive to Gaim Episode 40.

Man of the Beginning= Man Of The Beginning After Kouta receives the Forbidden Fruit and eats it, he turns into a white haired and silver armored version of himself, which looks similar to Kiwami Arms with a chestplate resembling part of Matsubokkuri Arms' breastplate. His right eye also becomes red in color, similar to the Woman of the Beginning. This is Kouta's most powerful form in that it has God-like powers. Shortly after this transformation, Kouta sends all of the Helheim plants and Inves to a distant planet and leaves with Mai to terraform said planet into a new Helheim. When Kouta returns to Earth, he is able to transform directly into Gaim Kiwami Arms either with a simple call of "Henshin", or by summoning his Sengoku Driver appearing with the Kachidoki Lockseed already in place before inserting the Kiwami Lockseed.

As a Man of the Beginning, Kouta is able to create new life with the same restriction as the Femushinmu Man of the Beginning, Rosyuo. This means he is unable to revive people if they die. Kouta manages to circumvent this by utilizing the Kiwami Lockseed such that whenever he dies, a simple activation of the Lockseed by someone (except for Megahex) would enable him to revive.

Appearances: Gaim Episodes 46, 47, Movie War Full Throttle

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Devices

 * Sengoku Driver - Transformation device
 * Removable slots for additional Lockseeds:
 * Genesis Core - Essential to access a Jimber Arms
 * Senyo Joint - Essential to access Kiwami Arms
 * Lockseeds - Gives access to Gaim's Arms changes, depending on which lock is used
 * Lockseed Holder - Carrier strap for Gaim's locks
 * Musou Saber Holster - Carrier strap for Gaim's Musou Saber

Weapons

 * Musou Saber - Gaim's side weapon in every single one of his forms
 * Arms Weapons - Weapons that come with the Arms, besides the Musou Saber:
 * Gaim:
 * Daidaimaru - Gaim Orange Arms' personal weapon and one of Kiwami Arms' personal weapons
 * Moldy Daidaimaru - Gaim Kabi Orange Arms' personal weapon
 * Pine Iron - Gaim Pine Arms' personal weapon and one of Kiwami Arms' personal weapons
 * Ichigo Kunai - Gaim Ichigo Arms' personal weapons and one of Kiwami Arms' personal weapons
 * Suika Sojinto - Gaim Suika Arms' personal weapon in Yoroi Mode and one of Kiwami Arms' personal weapons
 * Banaspear - Gaim Banana Arms' personal weapon and one of Kiwami Arms' personal weapons
 * Donkachi - Gaim Donguri Arms' personal weapon and one of Kiwami Arms' personal weapons
 * Duri Noko - Gaim Durian Arms' personal weapons and one of Kiwami Arms' personal weapons
 * Sonic Arrow - Gaim Jimber Arms' personal weapon and one of Kiwami Arms' personal weapons
 * DJ Gun - Gaim Kachidoki Arms' personal weapon and one of Kiwami Arms' personal weapons
 * Mango Punisher - One of Gaim Kiwami Arms' personal weapons
 * Budou Ryuhou - One of Gaim Kiwami Arms' personal weapons
 * Kiwi Gekirin - One of Gaim Kiwami Arms' personal weapons
 * Melon Defender - One of Gaim Kiwami Arms' personal weapons
 * Kagematsu - One of Gaim Kiwami Arms' personal weapons
 * Kagematsu Shin - One of Gaim Kiwami Arms' personal weapons
 * Kurumi Bombers - One of Gaim Kiwami Arms' personal weapons
 * Joeshuimu - Rosyuo's personal weapon briefly used by Gaim Kiwami Arms during his battle with Redyue
 * WizarSwordGun - Gaim Wizard Arms' personal weapon
 * Handle-Ken - One of Gaim Drive Arms' personal weapons (Movie War Full Throttle)
 * Door-Ju - One of Gaim Drive Arms' personal weapons (Arms Change series)
 * Drag Saber - Gaim Ryuki Arms' personal weapon
 * DenGasher Sword Mode - Gaim Den-O Arms' personal weapon
 * Ride Booker - Gaim Decade Arms' personal weapon
 * Trigger Magnum - Gaim Double Arms' personal weapon
 * Medajaribur - Gaim OOO Arms' personal weapon
 * Rocket Module - Gaim Fourze Arms' personal weapon
 * Musou Saber - Gaim Yami Black Jimber Arms' personal weapon
 * Sonic Arrow - Gaim Yami Black Jimber Arms' personal weapon (Kamen Rider Battle: Ganbarizing)

Vehicles

 * Lock Vehicles - Vehicles that unfold from special Lockseeds:
 * Sakura Hurricane - Gaim's main Rider Machine. It is lost during the final battle against Kaito Kumon. He evidently gained a new one when he arrives in the World of Build.
 * Dandeliner - Gaim's second Rider Machine. Loses it during the the battle against Bujin Gaim, but later receives another one from DJ Sagara. It is lost during the final battle against Kaito Kumon to an evolved Seiryu Inves
 * Tulip Hopper - Gaim's third Rider Machine
 * Rose Attacker - Gaim's unused Rider Machine, which is given to Decade to get Shu Aoi escape with him while Gaim prevents Fifteen from taking his son away from the lighthouse where Saki Aoi is.

Others

 * Reinbō Pasu (レインボーパス) - A special cellular-like device that all of the possess, functioning as their belt buckles and communicators. In the ToQger Vs. Gaim Special, Narutaki had an orange-colored Rainbow Pass before giving it to Kouta, allowing him to enter the Ressha, who then gave it to Mai to try to get her out of Zawame City. Given the fact the Rainbow Passes are the paper passes that Right and the others all used as kids, it's unknown how Narutaki gained one.