Revenge of the Bushido Blade (1980) [AKA The Last Reunion] [Blu-ray]

1945: the Philippines. Several members of a platoon of American soldiers not only kill a Japanese general, but also assault and murder his wife. The couple's son, Kimon, witnesses these ghastly events and vows revenge. Thirty-three years later the platoon get back together in Manila for a reunion. The adult Kimon also shows up to pick off the platoon members who butchered his parents one by one.