After losing her beloved husband, widow Chisato decides to return to her father-in-law's home. However, at her husband's graveside, she is sexually humiliated by her father-in-law, who verbally breaks her down while determined to make her his own. Trapped in a twisted, perverse relationship filled with obsession, Chisato endures repeated days of brutal training and tight bondage. What fate awaits her as she submits to this life of incest, BDSM, and sexual slavery under her father-in-law's control?