Momiji and Shigure probably.
Honestly its hard to say they make most of the characters complain about there own stories which makes them seem whiney, which as yet momiji and shigure haven't done.
Shigure is probably the funniest character in the whole thing and I like his laid back attitude. Momiji is a bunny which is kinda awesome. I was really hoping for a dragon to spice things up, although kitten decided to spoil that for me, so i'm not sure how i'd have reacted to that otherwise.
I kinda want to know where this is all going, but not much has happened in the first 2 volumes. There was just a lot of them going to school and not much really happening and then they repeated the story a few times, which because i read it in one go made it all seem paced badly. I'm hoping they will tell us why they are cursed real soon. That whole thing about Hatori going blind was mentioned a couple of chapters ago but they haven't explained it.