Hi I'm looking for a korean manga. The art style I remember reminds me of the one from "Hate Mate" and "A Declaration of Revenge" but it's not these artists.

What else i remember from the manga:

The (later) couple were childhood friends (?)
It's in black and white or sparsely colored.
Mafia theme.
I think at one point the MC supposedly died.

Please help me I rwally want to read this again!