Kate Burton is the lead character and the pilot of both Nemesis and Nemesis-R fighter crafts. Kate was born in 2000 in Gradius, being one of the few wreek survivors from the final fight of Space World War I, where he lost his parents while he was still 5 years old. Kate and the other surviving wreeks are housed by the Deep Science and enlisted in the Galaxy Federation. At the age of 12, he leaves the agency and enlists into the Deep Science, seeking to join the Gradius Empire to exact revenge on the ORN Empire who killed his parents.