Bichhoo (movie, 2000)

Jeeva is a small-time criminal who treasures his solitude, but perky girl-next-door Rani works hard to befriend her sullen neighbor. He rebuffs all her advances -- until a gang of criminals kills Rani's family. In a gross miscarriage of justice, the criminals are set free. Jeeva's sympathy for Rani quickly turns into feelings of love, and to prove his affection, he trains Rani as a weapons expert so she can avenge her murdered family.