It's a series of video games about an angry schoolboy, his peers, and rival schools. It started out realistic, with the proto-beat 'em up "Nekketsu Kouha Kunio-kun", but it eventually evolved into chibi, wacky sports games. Once in a while they went back to the "realistic" track, but not often.
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Ognimod
He looks like a Kunio-kun character! =D