A murder mystery following six pretty JK, who all have something to hide. The film's Japanese title literally translates to "pitch black girls", highlighting the characters personalities which soon become dark. One day, pupil Itsumi Shiraishi dies at the Seibo Maria Girls High School. The daughter of the school's administrator, Itsumi was envied by all the students there. Surrounding her death is a shroud of mystery; did Itsumi kill herself, was she killed accidentally or intentionally? At the time of her death, she held a lily of the valley flower in her hand. A rumour spreads that someone in the school's literature club, which Itsumi had presided, killed Itsumi...
Suzu is a shy, everyday high school student living in a rural village. For years, she has only been a shadow of herself. But when she enters "U", a massive virtual world, she escapes into her online persona as Belle, a gorgeous and globally-beloved singer. One day, her concert is interrupted by a monstrous creature chased by vigilantes. As their hunt escalates, Suzu embarks on an emotional and epic quest to uncover the identity of this mysterious "beast" and to discover her true self in a world where you can be anyone.