Haruki married Tomoo and moved into her husband's family home. Only her father-in-law and brother-in-law lived there, and Haruki, the only woman, had a big presence. One day, a masked man appeared and Haruki was raped. The one who looked after her was her youngest brother-in-law, Takahide, who should not have been at home. Takahide had been suspected of rape in the past and had been holed up in the basement ever since. Then, without knowing who raped Haruki, the family's dirty nature gradually became clear...