Based on the manga by Kudara Naizou.
Yukka, a young college student and Yazaki thought they would spend the rest of their lives together. But after a Zero Sum concert one night, Yukka is taken and gangbanged by the band members of Zero Sum. Yukka does not tell Yazaki as he seduces her again and again. However, the experience of the gangbang has aroused sexual desires within Yukka which leaves sex with Yazaki unsatisfying.
Yukka is torn between her love for Yazaki and her lustful desires for the rest of the band leaving her not knowing what to do...
