First appearance in manga: Chapter 1
First appearance in anime: Season 1, Episode 1

Jouichirou Nishi is a middle-school veteran of the Gantz world, having arrived there over a year before the beginning of the series. While running away from police officers after shoplifting, he fled onto an apartment building roof where he fell to his death.

Much like how Kurono started out, he is also selfish and has a Social Darwinist approach to life. Nishi is reluctant to reveal anything about the Gantz or himself, but he runs a web site where he posts information about it (carefully avoiding Gantz's rule about informing outsiders, which would in turn prove fatal). Gantz calls him "Mr. Nishi," which is rather interesting given how informally or derisively he refers to most of the other participants.