Yoichi Shiraishi, a lonely teacher in his thirties, enters into a secret and passionate relationship with his honor student, Sae Inagaki. Despite the risks of their forbidden romance and the antics of a supernatural toilet ghost, Sae's devotion leads them from clandestine encounters in the classroom to a lifelong commitment. Their bond eventually culminates in marriage and parenthood, turning a scandalous school affair into a devoted family life.