Wow. What episode, and what was going on?

Obviously, she showed up at school without her uniform, so an art class broke out.

I don't remember this scene in the series, so I'm removing the screencap tag until someone can cite an episode.

I found the episode. Season2 episode 8. This scene is part of a montage of the Jersey Club's activities after Reiko joins them and is clumsy at everything. That's probably why I didn't remember the scene, as I had forgotten everything about that montage before.