Tae Fujiwara lives alone with her stepson, Yoshio, while her husband is away on a work assignment. Though they are stepmother and stepson, Tae begins to feel romantic and sexual desires toward Yoshio, viewing him as more than just family. Unable to resist the provocations of her friends and overwhelmed by her own lust, she succumbs to her lewd impulses, writhing in helpless arousal. Yoshio secretly fantasizes about her, consumed by jealousy and desire, gradually descending into obsession. Amidst love, lust, and misunderstanding, their relationship takes a dark and twisted turn.