This facility is the only one in Japan that treats ejaculation-dependent prisoners. The inmates are prisoners who have been hindered by excessive sexual desire in their daily lives. This is a record of three years from the time O-san, a beautiful female guard working there, started her career to the present. "I myself will take sexual action against the inmates." A professional consciousness that never reveals emotions during working hours. Even when dealing with prisoners who cannot suppress their impulsive sexual desires, she performs business-like, cold, top-down riding SEX, and even when dealing with the prisoner's sudden immediate insertion, piston, handjob, and other random acts that make them cum, the female guard never breaks her expression. She doesn't show her expression even when she reaches climax. Instead of feeling and making a sound, she blows a whistle.