good cop in hong kong movie

When he woke up, Su Lehui found himself in Hong Kong Island in the late 70s.
"Am I a big shot in the film and television industry playing unspoken rules, or dabbling in shopping malls and becoming the world's richest man?" Su Lehui muttered to himself.
It was only when Su Lehui discovered that his playmate downstairs was named Chen Jiaju, and the girl he picked up on the road was named Cheng Ruoxin, did he realize that this Hong Kong Island was not the one he remembered.