Responses
do it be this one
https://www.mangago.zone/read-manga/flowers_of_evil/
I don't remember the first part, but maybe this:
https://www.mangago.zone/read-manga/aku_no_hana/
trying to find an old manga i read. it's about this really creepy girl of an outcast who spots one of her classmates jacking off or spraying his classmates uniform with cum. i think from there on they both team up to do creepy shit together. it had a timeskip with the girl missing and in the timeskip we see the guy get better and even start to date one of his school mate. it became a bit of a love triangle. it might have had Hana in the title. it was super popular back in the days. it gives off very similar vibes to oyasumi punpun