As Tears Go By (1988)

A low-level triad "big brother" has a hot-tempered "little brother" who can't keep out of trouble, and consequently is in constant need of being bailed out by his protector. The "big brother" is super cool, but lacks the ambition to rise in the ranks of the triad societies - and once he meets his cousin from Kowloon and falls in love with her, he even thinks about leaving "the life".