On her sixteenth birthday, Rin (Yumi Sugimoto), a bullied, timid schoolgirl witnesses her parents killed by fearful, anti-mutant humans. Rin's dormant mutant abilities are awakened and she is driven away from her hometown by an angry mob. She meets other mutants called 'Hiruko', and teams up with Rei (Yuko Takayama), a hardarse, rebellious type, and Yoshie (Suzuka Morita), a cute nurse who is conflicted about killing humans. Tak Sakaguchi plays Kasagari, an evil mutant who has an impotent sword growing out of his stomach. Originally trained by Kasagari, the three girls turn against him and his drive to turn Japan into a human-free zone and must fight him and his other loyal mutant minions.