I'm not sure where you read that, but was it really for Disgaea 2? There are fist users like Sinners (which you get after getting a felony in chapter 3, IIRC) and later on Ninjas and Kunoichis (who require some Weapon Mastery lvs), but I don't think they're the ones you're thinking of. I think Disgaea 1 had brawlers of both genders unlocked from the start, but I haven't touched that game in over a decade.

I think you are probably right. Probably remembering something from the wrong game. Shouldn't trust my memory.

This is actually the only game in the series with no brawler class. Instead you get the unlockable "Sinner", who is largely worse but has a secondary passive that boosts his team attack rate, which is the only reason he isn't completely worthless. He's replaced by the brawler again in the next game, who is much better than in the first game due to rebalancing fist weapons, adding evilities, and having stats and aptitudes that don't forever make them just worse fighters with fist specialization.