Wife-swapping village: The village I married into turned out to be a perverted community where wife-swapping and NTR (Netorare) were common forms of entertainment. (Shibasaki Haru, START-611)

Several months after her marriage, Haru Shibasaki moves to a remote mountain village in her husband's hometown due to her adoptive grandmother's illness. Although confused by the village's unique rules, Haru tries her best to integrate. However, on the night of the celebration party for the couple's move, she is forcibly assaulted by her husband's elders. This incident leads Haru to learn about the existence of a terrifying "sexual custom" passed down through generations in the village.