Despite knowing it's ethically wrong, Oosawa Yukika (a lewd wife) continues to repeat infidelity, breaking everything down as she lives. The secret and legend of her birth!! 15 years ago, when her mother was in childbirth, her father, who was aroused, took off her sailor uniform and she lost her virginity in the worst way. She dedicated her body and soul to her first love, her homeroom teacher, but in the end, he ran away, extinguishing her hope of living happily. Then, at the age of 18, Yukika faces a modified deathmatch with one woman against three men, risking her life and getting hurt!