First season wasn't nearly as bad with the tsundere. I don't think Shinku really counts. She didn't seem to have any trouble showing affection for Jun in the last two episodes(after he stopped being such as asshole), wheras tsunderes are supposed to be embarresed and conflicted.
Suiseiseki didn't start being wet for Jun until the seasond season, too.
Ah, that's another thing I forgot. Second season starts smelling a little bit like a goddamn harem series.