Yokosuka

Yokosuka (横須賀) is a minor character in Toaru Majutsu no Index. Member of Skill-Out and a self-proclaimed anti-esper battle expert involved with Academy City's darkness.

Background
He's the leader of his group in the seventh district; he addresses himself as Yokosuka The Organ Crusher (内臓潰しの横須賀) After Sogiita Gunha subdues Yokosuka's subordinates to save Haratani Yabumi, Yokosuka reveals himself and prepares to fight Gunha, only for Gunha to take him out in an almost comical fashion.

Toaru Jihanki no Fanfare
It is revealed here that he has developed a certain level of rivalry with Gunha, displaying enough persistence to challenge him 30 times; he has also developed his physical resistance to the point were he can take 10 Amazing Punches before being defeated.