In one episode, we see Rin Toyama laying on top of Kou Yagami, both wearing panties, as Aoba walks into the room. Rin and Aoba both freak out from this. Mostly played for comedic purposes.
There is frequent mild fanservice and occasional mild sexual innuendo.
One character is recurringly caught sleeping in her underwear while at work; the camera occasionally gives us voyeuristic close-ups on her panty-clad rear, but for the most part these moments are played for laughs rather than titillation.
Some brief references to breast size, usually referring to girls being jealous that other girls' breasts are bigger or smaller than their own.
One episode has the characters go to a bathhouse; parts of their (non-detailed) breasts/buttocks can be seen as they bathe.