My Date with a Vampire

Fong Kwok Wah is a Chinese guerrilla fighter from the time of the Second Sino-Japanese War. In 1938, he was fighting with Yamamoto Ichifu, a major of the Imperial Japanese Army, when they were interrupted by Cheung San, the progenitor of all vampires. The two men and a boy named Fuk Sang are bitten by Cheung San, and they become vampires.
In present-day 1998, Fong lives in Hong Kong under a new name, Fong Tin Yau. His physical appearance has not changed since 60 years ago. He works as a policeman while Fuk Sang lives together with him and pretends to be his son, who currently attends primary school. Fong meets Ma Siu Ling, the heiress of a clan of ghostbusters who have dedicated themselves to ridding the world of evil supernatural beings. Fong gradually becomes embroiled in a love triangle with Ma and Wong Jan Jan, Ma's close friend and confidante.