I'm looking for a manga I read a long time ago but I can't recall the name at all and would only be able to recall the art if I saw it. I remember small scenes where it was in like an apocalypse setting and the main character is a girl and she was in love with either a senpai or a guy she knew but the guy had a girlfriend. Forward to either a month or year the guy is part of some team that's like scouting the premise and I think he lost an eye. He and the girl reconnect but then an ex-girlfriend or current one confronts her on something. Not a lot to go on but that is as much as I can remember.

Ageku no Hate no Kanon

OMG yes, thank you so much! You are a lifesaver because it was eating at me that I didn't know what it was <3