Katsuhiko Jinnai is one of the secondary characters of the anime series El Hazard. Jinnai is a rival high school student to Mizuhara Makoto. Jinnai believes that Makoto is always trying to outdo him at everything he tries to accomplish. Jinnai is extremely competitive, and will do anything to win.
Jinnai eventually pairs up with the leader of the Bugrom, Diva. Diva is the queen of an evil clan of giant insects that plan to take over El Hazard. Jinnai becomes like the CEO of this clan, only because it may help him destroy Makoto.