Shinpei Ajiro returned to Hitogashima for the first time in two years after learning about the death of his childhood friend, Ushio Kofune. Shinpei, who attended the funeral, hears from his best friend that "her death could have been murder". Also, even Mio, Ushio's younger sister, suspects that she was indeed murdered. There is a legend in Hitogashima that those who see the "shadow" of themselves die. Mio says that she saw Ushio's "shadow" once.