The Kominato couple, who have just moved, hit it off with the couple living in the mansion next door. Despite being newly married, her husband, Yuzuki, had become impotent and they had no sex. When she was invited to swing by her neighbor, Atsushi, she awakened to an ntr fetish. The couple sank the pure and innocent Yotsuha into an immoral swamp, where she was made to experience pleasure with another man's dick...