Three yakuza brothers. The eldest one died and I think he or his father( its been a while since re read) made the stoic black hair guy to never lay his hands on family or those they consider as family. The promise came about because stoic guy's mother raped him for years until the big brother (yakuza head) found out.
Guy who saved the little girl (sad puppy face guy) was sold or kidnapped or somthi g and was drugged and...(you can guess). Threw himself out a window to escape and landed on car infront the brothers. The big bro told stoic face to keep him/help him.
Big bro died. Stoic face left yskuza so it didn't look like he had something to do with it. Bro. #3 (new yakuza head) pops in now and again. He still support the business financially from the countryside and protects his sister in law &niece. He likes the sad puppy face but refuses break his promise.
Tomato guy likes puppy face.
(I think most of this is right i hope. I have to read this again)
Tomato guy likes blond haired guy.

I totally forgot about this couple someone give me a summary