On his way home from jogging, "Rin" meets a student from the same apartment building. The student is intimidated by her great beauty and body. Seeing him like that, Rin feels aroused. Her fantasy and excitement grows day by day, and finally she takes him to her home and commits a lascivious act with him. The student's young cock turns her into a female and she repeats the sexual acts, but the man becomes serious and demands a divorce from Rin. The lives of the three, including her husband, are thrown into chaos.