未亡人の性 しっぽり濡れて (1998)

Masako, now a widow, inherits a student dormitory—but with a catch: she must serve as its manager and remain chaste for one full year. Among the residents is Keiko, a promiscuous young woman who frequently visits the male students' rooms to engage in illicit encounters. It is a provocative life in the dorm, but now, another woman threatens to shatter this precarious peace…