Actually,there is NO specific way to get X character by by treating it badly.And there is no way to get X character by treating it good.But oyajitchi is an exeption.I would recomend though to treat it as good as possible.If you get a UFOtchi that is a good sign.
i got my by ALWAYS making sure that the hearts are full and cleaned up its mess as soon as it "went" and pausing it when i cant give it all of my attention