Yoooo... I have so many thoughts about this, beyond what we actually see in the chap:
1. Is Koyoi just used to getting passed around like that? Is she just fucking around with guys, because that's the only way she knows how to get close to someone and she really needs someone to be close to her?
2. I'm reaching, but now that I think if it... do you think her dad... you know? I hope not, but there ARE some really dark themes in this manga sometimes.
3. I thought Isami would really go overboard and he probably did, that was rough, but at the same time, he looks beaten up. Not literally, just "by life". I never connected the 2 before, but that shadow trying to hang himself wasn't some kind of Tobio's imagination. THAT was Isami. I guess all of what happened really hit him the most out of the group.
4. Being so pushy with his GF is STILL terrible, of course, but I kinda get it. I hope they can all talk things through. If anything, one has nowhere to go and the other is suicidal. They could really help each other A LOT (even though they eventually WILL get caught).