Koichi, who felt emptiness in his daily routine of going back and forth between work and home, was subjected to a reverse molestation by a woman while commuting one day.Excited by the stimulating pleasure that he has never tasted before, he can not stand it and returns.However, the other party was Akari, a female employee of a business partner.Koichi, whose weakness is grasped, accepts the reverse lewd act on the train as he is told.Koichi gradually becomes absorbed in the perverted extraordinary life with her who blames her with her smile without hesitation.