In the plot, Hajime and Rei are friends, both living in the same building, both coming from very humble backgrounds, and both with broken families having just single parents, a Mom and a Dad, that eventually get together in an affair. However one day the parents suddenly disappear and the 2 friends are left alone, not knowing any better they begin to pass the days f*cking. A few days later, the abusive Father of Hajime eventually returns not realizing that things have already changed a lot.