The Lonely Killer (1977)

When Lin and his bride are murdered during their honey-moon in Macao by three Japanese rascals Yamamoto, Kijima and Sazuki, the murderers want to flee back to Japan; but the Hong Kong police can't get the evidence to stop them. Inspector Tsung Hsuan-tung, one of Chen's best friends quits his post and goes alone to Japan to probe the case. Tsung Hsuan-tung is so angry that he intends to shoot the murderer by himself but stops by his Japanese friend Takase.