Living with her stepson Ryota while her husband is frequently away on business, Chihiro struggles with loneliness and anxiety, her relationship with Ryota growing increasingly strained. Seeking to fill the emotional void, she rediscovers herself through an affair and falls in love again. But when Ryota discovers her secret and obtains video evidence, he begins to blackmail and dominate her. Forced into humiliating blowjob sessions, tortured with sex toys, and brought to the brink of orgasm only to be denied release, Chihiro is gradually broken down by his escalating cruelty. Ultimately, she is raped and mercilessly humiliated, descending into a nightmare of suffering and degradation as Ryota turns her into his sex slave.