Best known to to most overseas fans as the source material of the Superhuman Samurai Syber-Squad TV series, the series follows three tech-savvy kids, Naoto, Yuka, and Ippei who created their own videogame superhero, but then discover it possessed by an inter-dimentional police officer named Gridman. Pursuing an evil program called Kahn Digifer, he merges with Naoto and fights Kahn Digiger's digitized monsters in order to prevent the computerized demon from wreaking havoc on the Human World.
[Source: Tokusatsu Network]