|This article is about a/an rider in Kamen Rider Wizard.|
|Kamen Rider Beast|
|Series:||Kamen Rider Wizard|
|Rider Type:||Anti-Hero (First)|
|Homeworld:||Earth (Main Timeline Continuity)|
|First Appearance:||Kamen Rider × Kamen Rider Wizard & Fourze: Movie War Ultimatum|
|Last Appearance:||Kamen Rider × Kamen Rider Gaim & Wizard: The Fateful Sengoku Movie Battle|
|Number of Episode|
Full list of appearances
|Actor:|| Tasuku Nagase|
Kirato Wakayama (child)
|Kamen Rider Beast|
- "Now, It's breakfast time!"
- ―pre-battle catchphrase when it is morning time[src]
- "Now, It's lunchtime!"
- ―pre-battle catchphrase when it is noon[src]
- "A pinch is a chance."
- ―Kosuke's words of hope[src]
Kosuke Nitoh is the secondary rider of Kamen Rider Wizard, Kamen Rider Beast. 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 ancient magician" by the Wiseman due to his ancient Belt, he needs to absorb the mana of the defeated Phantoms in order to regain his strength.
Kosuke Nitoh 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.