En forlystelsestur om at blive voksen. Cootie, en fire meter høj, ung, sort fyr i Oakland, CA, er vokset op i det skjulte, og oplever skønheden og modsætningerne ved verden for første gang. Han former venskaber, finder kærligheden, navigerer akavede situationer og møder sit idol, en ægte superhelt, ved navn Hero.

Three computer-savvy kids, Naoto, Yuka and Ippei created their own videogame superhero, but then discover it possessed by an inter-dimensional police officer, Gridman. Pursuing an evil program called Kahn Digifer, he merges with Naoto and fights Kahn Digifer's digitized monsters in order to prevent the computerized demon from wreaking havoc on the Human World.