Yuuichirou Takiguchi
Boy #13 Yuuichirou Takiguchi, an otaku, is very naïve and a bit too friendly. He hides with his friend Tadakatsu. In the novel and manga, when Mitsuko attempts to kill Tadakatsu, they capture her. Yuuichirou sympathizes with Mitsuko, and intervenes when Tadakatsu tries to kill her. Tadakatsu accidentally shoots Yuuichirou, and then Mitsuko kills Tadakatsu. In the novel, Mitsuko kills and kisses Yuuichirou, while in manga, Mitsuko rapes an injured Yuuichirou before killing him. (Source: Wikipedia)