I have not watched How Long Will I Love U but It sounds like the Meet Me @ 1006 and How Long Will I Love You have the same concepts of time travel. With merging of apartments, going in and out of certain doors leads to different time periods, etc.
While HOTD is much heavier/darker in tone, both movies are about a house with parallel times and the choices the main characters must make as a result.
Both feature a time slip bringing the leads, who are a few years apart, together, and results in them having to cohabitate. Both stories have a similar feel and tone.
Both have the concept of an apartment fusing into another home which crosses two different time lines together and allows the ML and FL who are from different times to meet.
Both are subtly romantic stories featuring unusual forms of time travel (time slip vs. time loop) where the FL and ML must work together to change fate.
They both have time travel! Different genre's though, How Long Will I Love U is more of a melodrama with alittle comedy, while How Long Will I Love U has more comedy with some melodrama.
