I don't usually bother with last names and no one calls me by mine. That's the first thing about manners, right? [ The only ones in the SSS she calls by their last name are Otonashi and Hinata, actually, the ones she has closer connection to. Well those two and Naoi, but he's a butt. ] As long as we don't go treating each other like dirt I don't mind. Manners kind of distance people, don't they?