In Tokyo in the 90s, the city center has been suffering from a continuing depopulation. Also affected is Udagawa Junior High School where only six people are left. Their class leader, protector, and very good friend Masato died in an illegal skateboarding race. Five months later, Eito Hachiya, nicknamed Eight or 8, enrolls in school and wants to find out what happened. He even just looks like Masato! But mysteries surround him: Why does he know all the other six? Why can't they remember him?