Following the death of his daughter, Assistant Inspector Yamada Hajime has lost hope in everything, and jobs like closing under-aged prostitution rings don't exactly help matters. But there he meets a girl who looks alarmingly like his late daughter. Her name is Umino Shiori, a runaway girl who's desperate enough to sell herself to escape her house but won't tell anyone why.
Satsuki, a boy high school boy and his childhood friend are riding in an underground train until it suddenly stops. Upon closer inspection the denizens of the train discover a mysterious beast! Panic sets in as the passengers struggle to survive the beast and escape to the surface.