Married woman Yumi (26) is in her third year of marriage and satisfied with her sex life with her husband, but she receives a request from the organizer of a swinging club to be cuckolded. While still on the phone with her husband, her sensitive body is teased, producing wet, slippery sounds and moans of pleasure. As she begins sucking the man's cock, her expression turns lewd, and upon begging, "Please fuck me... I want it inside," she gets exactly what she desires—penetration that makes her writhe uncontrollably. Overwhelmed by waves of pleasure, she twists her body side to side, climaxing repeatedly. After relaxing in the bath, she cheerfully plays with the man's cock before taking it inside once more, arching her back and screaming as she reaches multiple orgasms. Caught between shame and guilt, the story captures how this married woman fulfills her deepest desires.