Ai, an honor student and class vice-president, visits the home of her shut-in classmate, Nozomu, to deliver handouts and persuade him to return to school. However, after Nozomu's uncle lets her inside, she is led to a room and locked in from the outside. Nozomu begins to ravish her like an animal given prey... Furthermore, she is continuously raped by his uncle and brother, awakening her masochistic side, until she eventually falls so far that she begins to crave pregnancy herself...