Hanamaru has been dropping hints that she's mad. Pretty obvious ones, actually. Like she didn't smile when Yoshiko told her good morning, and stuck by Riko's side at lunch time, and has been periodically shooting glares in Yoshiko's way just in case she happens to catch them. Everyone but Yoshiko has already asked her what the matter is, and that's only been making Maru more mad.

They have library duty after school today, and while that's usually one of the high points of Maru's week, being alone with Yoshiko right now, in that sort of atmosphere... as soon as they set foot in the library, it's already stifling.

She could bring it up herself. That would make it quicker, probably-- Yoshiko has always been bad at cluing on to this stuff. That would be the more mature thing to do, Maru is aware, but instead all she does is point down the library and say:

"Well, I'm gonna go sort the books over there, okay?"