Kōsuke is the executive committee member of the student council. He is very tall and muscular, well versed in using weapons, and has a major quirk of speaking a lot of English (he even sings a tune in English in one episode).

"Beatrice". It is a mysterious power that responds to people&rsquo;s will and realize all of them. Tokyo Beatrice University Attached High School is the only school that teaches Beatrice called "magic appears in the real world". 
Yoshimura Mamoru is a high school boy who was saved by Beatrice miraculously when he was a child. At the first day of the school, he meets a girl under the cherry trees on his way to the school. She orders him to go out with her. 
Her name is Takasu Ayako. She is in the second grade and one year older than him. She is a director of student committee of discipline. Also, she is a granddaughter of a big-name politician, very beautiful, and a genius Beatrician who can even shoot a satellite down. She is called Witch Beatrice or Death Angel in Beatrice, but in fact, she is a pure-hearted girl. 
(Source: AnimeNfo)

Also goes by the names Shintaro Ohata and Shintarou Oohara.

Kosuke Yagi