The biggest problem about this...[SPOILERS]
in my opinion is the reason why the little girl likes the dude.
In that, there wasn't one.
She just hits on him for no reason one day, a stranger on the bus. Then their awkward relationship flourishes... but we don't know why. At least the dude manages to slip in a few half-assed reasons. But mostly, it's quite obvious why a hetero dude would be attracted to hayden's character: she's cute and is friendly. That's reason enough.
But why is she attracted to him? He's disheveled and a bit of a sardonic jerk. Absolutely no reason is indicated why she likes him, not even an "I don't know why, I just do" reason.
So how am I supposed to root for their relationship when I can't comprehend how it even exists in the first place? I suppose it was intentional to portray her this way, because all the other characters' motivations were explained. The girl in the bar was curious. The karaoke girl is a prostitute. Kelly Hu likes his humor.
So if I missed it, someone please enlighten me, because that lack of clarity caused a confusion that ruined an otherwise enjoyable film for me.