Set in a fictional European country in 1924, a Japanese exchange student meets a mysterious, brilliant girl who only leaves the library to sleep. Her brother, a detective, relies on her exceptional mind to solve difficult mysteries.
Four girls take part in illegal underground fighting event "Girl's Blood" held at an abandoned school building in Roppongi every night. The girls have their own stories and quirks from their private lives. Satsuki (Yuria Haga) suffers from a gender identity disorder, Chinatsu (Asami Tada) ran away from an abusive husband, Miko (Ayame Misaki) is a S&M queen and Mayu (Rina Koike) has a Lolita face.
As a young child, Hana loses her family to a devastating tsunami that wipes out her town. At a shelter, distant relative Jungo sees her wandering and adopts her as his daughter.
