There is a man who was a mafia hitman aka assasin

he loves a woman who was a mafia daughter

but he decided to not love her because he lead a dangerous life

the woman then married with the man boss

the boss and the man respect each other and the boss promised to protect the woman

both the woman and the boss have a daughter

the man then somehow died in his mission, betrayed by his best friend, the woman was so mad to the point she get a gun and want to kill the man killer but got stopped by the boss because she will got killed.

16-18 years later, the boss and the woman got murdered by another mafia organization lead by the man best friend i think

suddenly when the daughter will get killed, the man come and saves her

it revelaled the man got revived as vampire/ghoul or something undead like that and he swore to protect the daughter

in the end both of them faills in love

Sounds a lot like Gungrave... But I don't think that's the one you want.

~4400 manga completed
~1700 ongoing...

hey thanks