Because

You'll know if you know the story

Yeah, have you beaten the main storylines?

Maybe it’s under her hoodie?

Also have you beaten the main game ?

I don't think wearing uniforms is a requirement.

It actually is

Well, it's a long game, so I don't think most people can remember every single detail.

Director Clavell made a deal with them to not wear school uniforms as long as they participate in community service

The rules don’t apply to Penny