So far:
We know Kurumi experiences psychological abuse from her mom and Naoi First name pending appears to be experiencing physical abuse (bruises on her arm at the end of ch 1, teachers comments on her family)
Unclear if Naoi actually wants to get Kurumi in trouble, because she lied about their first talk to the teacher before she had the video (and seems to regret decking kurumi for about .25 seconds); that being said she definitely has a sadistic personality and certainly has a lot to make up for
Kokoro is perfect and has a bunny pin and a carrot pin and must be protected at all costs
My guess is they pick up on each other’s abuse and they start increasingly literally Being gay and Do Crimes, though I do hope it gets there sooner rather than later otherwise it could get a little too torture-porn-esque for my own personal tastes but I’m definitely interested so far 👍