Your initial hook is great; you're an amnesiac vampire in 50s Hong Kong just promoted to a missing person, and fate brings you together with a triad boss. If that doesn't hold attention, nothing will.
Just after the bodyguarding relationship was established, I was stoked to set out into the city, but we had to chat with Saan, and gripple with our vampiric nature first. Which again I understand is a necessary step, but some interactivity wouldn't be remiss between the two story beats.
But plot is always a very subjective thing, so I leave you to it.