The time is a little while ago in Tokyo. A mysterious thief who specializes in art, known as "Red Dragon," is making waves in the world. Meanwhile, Kichikoji Kaho, who lost her parents in an accident, has a treasured ukiyo-e print stolen by Red Dragon! Kaho visits the famous detective Ushijima Raizo to get the painting back, but he asks her, "Can you sell yourself to me in exchange for lending me your help?" A love triangle between a detective, a thief, and a rich girl!