Summary: High school student Mirai finds that her schoolmate Akihito is an immortal being and half a spirit. When Akihito learns that Mirai is a spirit world warrior their lives become intertwined.

Summary: Four high school students: Haruka, Makoto, Nagisa and Rin, all took part in a swimming tournament shortly before the end of high school and then lost touch with each other. Years later, they reunite.