Boy #13 Yuuichirou Takiguchi, an otaku, is very naive and overly friendly. He hides with his friend Tadakatsu.
In both the novel and manga, when Mitsuko attempts to kill Tadakatsu, they manage to capture her. Yuuichirou feels sympathy for Mitsuko and steps in to stop Tadakatsu from killing her. Unfortunately, Tadakatsu accidentally shoots Yuuichirou during the struggle. In the aftermath, Mitsuko kills Tadakatsu.
In the novel, Mitsuko kills Yuuichirou and then kisses him, while in the manga, she rapes the injured Yuuichirou before ultimately killing him.
(Source: Wikipedia)










