Five years into her marriage to her kind husband Takuro, Akari finds their married life peaceful but unsatisfying—his gentle lovemaking leaves her craving more. One day, a female friend suggests, "Why not try cheating? It might be fun," sparking Akari's curiosity about infidelity. Hearing that finding an affair partner is difficult, she approaches her former colleague, the flashy and cocky Kida-kawa, and asks him for sex. Thrilled by the fresh, intense experience, she gradually becomes emotionally drawn to him. She then seduces her admired boss, becoming deeply captivated by his refined, gentlemanly style in bed. Though guilt over betraying her husband lingers, she begins developing genuine feelings for her boss. One day, her husband surprises her with tender affection on their wedding anniversary, reminding her of the warmth and happiness they share. Her emotions briefly return to him. Yet, she realizes that marital happiness and sexual pleasure are not the same—and continues her wild, abnormal encounters with the flashy Kida-kawa.