In a crowded train, swirling with desire, stands a man with his hood pulled down low: Kusakabe Kiichi. His eyes see through women's desires, and with his masterful finger techniques, he lures them into pleasure. Fudou Iori, a student at Reimeikan University, doubts the existence of XX. There's no way XX exists. It's an urban legend. While investigating its existence, she encounters XX and is saved by Kiichi, who is also XX...