Karen and her husband, Hiroshi, have to borrow the bath from the Kaneda family who live next door for a while because the bath at home breaks down. Mikio, the eldest son of the Kaneda family, has long admired Karen, and when he sees her defenseless after taking a bath, he begins to have even more sinister delusions. One day, Mikio was spying on Karen while she was taking a bath, and Karen caught her. Mikio was prepared to be scolded, but what came out of Karen's mouth was something unexpected...