A female insurance saleswoman named Nina Nishimura is a masochist. However, her work performance has been declining while she feels increasing stress and pressure. One day, her boss and lover Kashiwagi suddenly breaks up with her. Unable to contain her masochistic desires, Nina visits Kashiwagi, whom she dated in college and was also her first master. After being reacquainted through passionate training sessions, Nina begs for even more intense and dangerous lessons, realizing that she can never go back to normal... #elderlyP