My sister, who is crazy about nipple play and has returned home after her cohabitation ended, is seducing me and asking me to help her with her nipple masturbation. Sumire Kuramoto

The movie revolves around the complex and intimate relationship between a brother and sister, Yuuta and Sumire, after she returns home following the end of her cohabitation. Sumire, having a strong interest in nipple play, begins to seduce her brother, creating a tense and dramatic situation within their household. As they navigate their feelings and boundaries, the story explores themes of taboo desire, sibling dynamics, and personal growth.