Hiroki Yamamoto (44) and his wife Hinako Yamamoto (30), a couple with an age gap, take in their nephew who is preparing for exams. Their normally loving relationship begins to shift dramatically with the nephew's presence. The teenage boy becomes obsessed with his aunt, who casually does housework wearing nothing but panties, often without a bra. He starts secretly filming her. Gradually, he notices his uncle's deeply perverted side, and before long, this escalates into NTR forced intercourse with the sleeping wife. Packed with taboo thrills hidden within ordinary daily life, this story depicts how the once-intimate marital bond is systematically violated by the nephew.