Kaoru Tono heard a rumor: The laws of space and time mean nothing to the Urashima Tunnel. If you find it, walk through and you'll find your heart's desire on the other side.in exchange for years of your own life.

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...