I don't know if I remember there being mafia, but maybe this? Fits a bit of your description
https://www.mangago.zone/read-manga/kare_no_shousou_to_koi_ni_tsuite/
It wasn't Japanese, it was a Korean webcomic ╥﹏╥ I've been trying to find this for a year y'all :( ty though!
Alright y'all I found it! Finally, it was escape into oblivion.
Congrats! A year paid off lol
that's literally one of my fav bls i cant believe i couldn't recongnise it
Pls y'all in trying to find this BL. It's black and white it's not zero whatever or red line?. The bottom is pretty toxic but so is the top. I think it opens up to them like having sex. They used to be friends maybe, they're on and off then they work on their problems and have a healthy relationship. Top might be in some sort of Mafia, gets beat up to get out? Maybe.