I don't really get all the people saying the new girl is nice. I have a little bit of sympathy for her situation, but it's pretty limited. I've never been that impressed by "Oh poor me I'm always number two"--do those people ever have any sympathy for the people further down? They do not, and she's no exception. Plus, the reason she wants to be number one is a smidge of hypercompetitiveness added to a bunch of need for adulation--she wants all the fans so she can bask in the attention and love, none of which she plans to return. She's a self-centred narcissist; how is that "nice'?
She isn't a character who IS NICE, she is a character who has NICE CHARACTER DESIGN--she LOOKS pretty and inoffensive, and she didn't ever QUITE look yandere when she said some of the creepier things she said. So, enough to be "nice" I guess?