Kosuke Nitoh

Kosuke Nitoh (仁藤 攻介) is the secondary rider of Kamen Rider Wizard, Kamen Rider Beast (仮面ライダービースト). He lost his powers during the final battle with Wiseman. He regained his powers sometime before Kamen Rider × Kamen Rider Gaim & Wizard: The Fateful Sengoku Movie Battle. Referred to as "the primordial magician" (古の魔法使い) by the Wiseman due to his ancient Belt, he needs to absorb the mana of the defeated Phantoms in order to regain his strength.

In Kamen Rider Wizard in Magic Land, his counterpart is referred to as the Golden Magician (金の魔法使い), a nickname he shares with Orma.

Kosuke Nitoh
He is a student archaeologist who is rather optimistic, believing staunchly that danger & opportunity are two sides of the same coin.

Ever since he found a fossil near a lake as a child, Kosuke dreamed of becoming an archaeologist. Though his parents approved his ambition, his grandmother did not. Because she also scolded his adventurous behavior, Kosuke grew up thinking of her as strict and mean.

During one of his expeditions, Kosuke accidentally discovered the Beast Driver in ancient ruins. He also has an unusual liking for mayonnaise, constantly carrying a bottle of it with him and putting it on any food he eats, including doughnuts, oden and foods that already have mayo. Haruto and Shunpei refer to him as "Mayonnaise" because of this unique habit. When he finds Phantoms or Ghouls, he refers them as his "food" due to his ability and need to absorb Mana from them. It's shown that when Haruto finds Phantoms and tries to defeat them, Kosuke will get angry for interfering with his "feeding time". He also constantly leaves everyone around him speechless due to his tendency to interrupt others and express his thoughts without breaks.

While he originally saw Haruto as a nuisance, he was nevertheless willing to cure him of the poison injected into him by Manticore through the use of Dolphi Mantle's powers. After the incident with Oikawa, he gradually warms up to Haruto and sees him as a rival as well as a friend. Initially homeless and having to camp in places until he got chased away, he found a permanent spot to set up his camp at the roof of a building belonging to a woman whom he had once saved. Though, he still prefer to camp in many places.

Later, Kosuke revealed to Haruto, Shunpei, and Rinko that he received Kamen Rider Beast's powers from Beast Chimera. The Beast Chimera made a contract with Kosuke, granting Kosuke his magic. In exchange, Kosuke must absorb mana by defeating Phantoms and ghouls, or he will be eaten by Beast Chimera. Unlike Haruto who is knowledgeable about how Phantoms come about and operate, Kosuke initially knows nothing other than they can take human forms and he needs to eat them to survive. Later, Haruto offers Kosuke to get rid off Beast Chimera. However, Kosuke refuses and prefers to retain his powers and the status of being both a rival and an ally to Haruto. Even when he lost his Beast Driver. Kosuke refuses to destroy Chimera, as he won't find any important discovery, like Beast Chimera.

History
He is young man from the Fukui Prefecture who is rather optimistic, often believing that pinches and chances are sides of the same coin. He has a gigantic appetite and an unusual liking to mayonnaise, putting it on everything he eats, including doughnuts. He originally lived with his grandmother before he became a student archaeologist. During an expedition, Nito found the Beast Driver and broke the seal holding a horde of Ghouls at bay. Forced to become Kamen Rider Beast to defeat the monsters, Nitoh learns he unknowingly forged a pact with the Phantom Beast Chimera and must now consume other Phantoms for their magical energies to keep the Phantom fed, as if it dies, so will he. Through a misunderstanding as to how Kamen Rider Wizard functions in regards to absorbing and replenishing magical power, he labels Haruto his "eternal rival" when they first meet after Nito was targeted by Manticore on the assumption that he was a Gate. Despite it being possible for Haruto to simply use an Engage Wizard Ring to enter Nitoh's Underworld and destroy Beast Chimera, Nito initially refuses on the grounds that his Phantom would be too strong for Kamen Rider Wizard to handle and the experience would "leave a bad taste." Nitoh later explains that as an archeologist, he wishes to learn more about the Phantoms, the Beast Driver, and the Wizard Rings, believing he will never make as important a discovery as Beast Chimera again.

When Nitoh attempts to end the second Sabbath, he is overpowered by Fueki. In risky gambit that could have killed him, Nito broke the Beast Driver to release Beast Chimera so he can devour all of the excess magical energies generated by the Sabbath to negate the ritual. In appreciation, the idea of eating not amusing, Beast Chimera spares Nitoh's life and frees him from their pact before leaving. Despite being a normal human again, Nitoh aided Haruto during the final battle. Once the Phantoms are finally defeated, taking Yuzuru as an apprentice, Nito decides to find Beast Chimera to learn more about the ancient Phantom. Nito eventually recaptures Chimera and seals it on the Beast Driver once more, but is forced to transform into Kamen Rider Beast once more to confront the Phantom Ogre and a copy of Koyomi he created using the Hope Wizard Ring, despite knowing that without Phantoms to consume, he will be eventually eaten by Chimera. After Ogre is defeated, he is consumed by the Nepenthes Inhumanoid under Kamen Rider Bujin Gaim's orders. Nito is later rescued by Kamen Riders Gaim and Wizard and assists them to defeat Bujin Gaim and in the occasion, learns that he can feed Chimera not only with Phantoms but with fruits from the Helheim Forest as well.

Kamen Rider: Summonride
Kamen Rider Beast appears as a Partner Chip in the video game Kamen Rider Summonride. Beast is a Luck (Yellow) Nakamaride chip, and acts as a light combat partner. His most common attacks are using the Chameleo Mantle.

Kamen Rider: Battride War
Kamen Rider Beast appears as a Second Rider in the video game Kamen Rider: Battride War. He is the one of the four second Neo-Heisei Riders who can be recruited into the Rider gang. He is first appeared as a brainwashed boss, until he was freed and unlike the movie Riders, he apparently made it way to join the other remaining main and secondary Neo-Heisei Riders, including surviving second Heisei Riders (such as Kaixa, IXA, and Garren) whom appeared as assist characters only.

In the game, Beast's mantle used for specials and finishing moves. While the mantles are unused for long, they will disappear. Ironically when Beast using his ultimate attack while wearing some of his mantles, the screen will shows a mantleless Beast.

His Hyper form is often usedas a separate DLC character, like Wizard Infinity Style to original Wizard, the form has no connection to original Beast. Same thing with Wizard, Beast Hyper is still voiced by Tasuku Nagase.

Unlike the other Riders whom has a bike (while Accel is a bike himself) Beast's Falco Mantle is used as his bike & moves like a normal walking inputs, as well as able to used dash attack, including an aerial attack, which the normal attacks can do in one hit (while without Bike Mode as original Beast can do 2-string normal aerial attacks like Blade, Decade and Wizard Infinity Style does). If playing Beast Hyper during Bike Mode, he will change into his Falco Mantle with the Bike Mode playterm being the same as original Beast. When Beast Hyper (during Bike Mode as original Beast + Falco Mantle) deactivates Bike Mode or using original Beast's special aerial attack, Beast will revert back to Beast Hyper.

Kamen Rider Batton-Line
Kamen Rider Beast becomes available in the Rider roster in the online PC game, Kamen Rider Batton-Line, after defeating the boss at level 10.

Kamen Rider Travelers Record
to be added

Kamen Rider: Battride War Genesis
to be added

Personality
Unlike Haruto, Kosuke is a much lighter character. He contrasts Haruto by being much more sensible and open to the others. Kosuke often places mayonnaise on all food, claiming that mayonnaise is the tastiest food. He even teases Haruto by placing mayonnaise on his doughnut; something that Haruto dislikes. Despite his lighter personality, Kosuke is a very stubborn guy and never listens to the others. He usually says "Don't say it!", to cut his conversation with the others. This can cause trouble for him and others, as in the first few episodes he appears in he often cuts off any conversation about Phantoms and Gates. He also doesn't take battles very seriously until the last few episodes, particularly after Yuzuru was kidnapped by the White Wizard. Despite claiming Haruto as a rival in the first place, Kosuke in the end helps Haruto in exterminating Phantoms. Kosuke is also easily or usually swayed by girls, like Rinko and Mayu. Despite this, his habit only happens for one person at a time.

Mantles
Unlike Wizard, Beast doesn't use alternate forms to combat the Phantoms he consumes. Instead, he uses single shoulder mantle armaments called Mantles (マント) to help him gain an advantage over his foes.

Kamen Rider Beast's ending theme is entitled "BEASTBITE".

In a feature exclusive to the S.H. Figuarts, Beast can be armed with Two Mantles (any combination). He can also use a single or Two Mantles in Hyper.

Devices

 * Beast Driver - Transformation device
 * Wizard Rings - Gives access to Beast's Rider forms and mantles.
 * Wizard Ring Holder - Carrier strap for Beast's rings
 * Griffin PlaMonster - Kamen Rider Beast's familiar.
 * Mirage Magnum - Kamen Rider Beast Hyper's weapon.

Weapons

 * Dice Saber - Kamen Rider Beast's weapon.
 * Mirage Magnum - Kamen Rider Beast Hyper's weapon.

Portrayal
Kosuke Nitoh is portrayed by Tasuku Nagase (永瀬 匡). As a child, Kosuke is portrayed by Kirato Wakayama (若山 耀人).

As Kamen Rider Beast, his suit actor is Jun Watanabe (渡辺 淳), which the role he reprises first in Movie War Ultimatum. His first Secondary Rider role, he is also the suit actor of the White Wizard, as well as Phoenix and Wiseman. His understudy is Kazuya Okada (岡田 和也), who is also Gremlin's suit actor.

Rider Machine

 * Beast has not been shown to have a motorcycle, making him the second Secondary Rider to lack a Rider Machine (the first being Diend).
 * This is teased in episode 40, where Beast borrows a bicycle to fight the Ghouls.
 * In the video game Kamen Rider: Battride War, the Falco Mantle is used in the place of a bike, further poking fun at Beast's situation.