Angel Heart
I randomly stumbled over this manga/anime and found out it's a kind of sequel to Cityhunter (one of my favourite anime), although I read somewhere that it's in an alternative universe and starts with "what if Kaori died?"
No!!! Too sad. T_T
But since it's Cityhunter, I can't help taking a look. The sequel is much darker and more violent, although the humour is still there, and most characters show up. Main character is a girl who has an even more tragic background than Ryo. In this story, he plays more of a fatherly role.
Watch the anime here.
Or read the manga here.