Mariko is living the life of a typical Japanese college student in the 70's, spending far more of her time balancing boyfriends and part-time jobs than on her schoolwork. She finds herself torn between a former boyfriend who's the tough, insensitive-but-sexy, type, and a new acquaintance who's more sensitive to her feelings, but who still acts childishly selfish at times. Will she choose one of them, or decide to go her own way?

Ryuko, a plain and introverted college student. One day, Ryuko accidentally witnesses a gang rape committed by the three popular students. Impulsively, Ryuko pretends to be a victim and reports the three to the university, succeeding in getting them expelled. Five years later, Ryuko catches the eye of Okino, a powerful figure in the business world, and under his protection, she thoroughly refines her appearance, shedding all her former awkwardness and transforming into a sophisticated beauty. As Ryuko enters high society, the three men she expelled reappear before her. This time, Ryuko is in control, skillfully seducing and manipulating the three while quietly plotting her perfect revenge. However, when the real victim, Miyako, suddenly appears, Ryuko's deception begins to unravel, and the intricately intertwined threads of fate start moving in an unexpected direction. What will become of Ryuko's butterfly-like transformation and revenge drama, which began with impersonation?