in ep 15, the ritual (around the 7, 8 min mark) includes clothed intimacy (one of the participants' b*****s are skimmed over, they get in a sexual looking position)
Some of the girls get clothes designs that are essentially bondage gear, notably skin tight material and visible panties
-ish; a female character expresses shame at the male love interest seeing her body because she feels he won't like it as it's 'too masculine and muscly' for a woman.
In ep 10 around the 18 min mark the protagonist accidentally walks in on a naked girl about to take a bath. The scene is set up to be the usual naked-but-not-naked fanservice. As he runs away there's a camera pan down her naked back to her backside. Scene lasts for about a minute.
Something similar occurs in ep 16 (around 16:30)