there's a manga.. there's a girl.. she has a fiance.... the fiance is scared of blood.. but, in fact, he will go wild when he sees blood. he's also the family member of mafia..

another story.. there's a manga.. there's a girl and a boy from 2 families that were enemies and want them to marry to peace the war..the pair always fight but in the end, they're in love with each other.. It's probably a one-shot or simple chapters

I'm also looking for something about love & mafia.. I want shoujo.. NOT SHOUNEN!!!

I'll be appreciating whoever that help me.. coz, every time you guess is answering my third question!

Maybe Change 2?

________________

That's Nisekoi (KOMI Naoshi).

I believe that is the one you are looking for
Nobara no Hanayome

As for other shoujo ones...
Oresama Teacher - school gangs
Inchou no Himegoto abrupt ending though...
Ah! Itoshi no Banchousama - school gang

For other mafia series, try
Arakure

or look for it in the categories search

THANX!!! It's Nisekoi & Arakura!! Thank you for other suggestions!! I'll read it when I have time!!

I would try Tokyo Crazy Paradise

second Tokyo Crazy Paradise
also Gokusen (not shoujo, but not violent shounen either)