Flower, the legendary assassin. He is cruel, ruthless and has no mercy on women or children. He is said to have honed his killing skills in Mexico and to disappear after leaving a flower at the scene of a murder. No one knows what this means, but Flower's name has become an urban legend in the underworld. One day, Momoko, a female assassin, receives a request to eliminate Flower and confronts him. However, her true identity is completely different from the rumour.