This was a well-crafted and well-acted short-length drama that makes you want to go back to the beginning and rewatch it again from the ML's perspective and knowledge of their past. (Which I did immediately.)

While somewhat predictable, there was still something about the way this time travel tale was told that felt different from your conventional C-drama time travel stories. And while the open ending may not be to everyone's liking, it felt much more impactful and moving -- so much so that I bumped up my original rating (after ep 23) from a 7.5-8 to an 8. The letter was tragic yet beautiful as it showed that he found closure figuring out what happened ("love is bitter, but I do not regret it") and it also gave Mo An'an the much needed closure she was looking for as well.

In that sense, it was a happy ending for me because we learn of Xiao Chu's real fate, even though it is simultaneously heartbreaking to think that he spent his life solving the riddle of Mo An'an and her appearances in his life.

My biggest "quibble" would be that I found it frustrating at times to watch history repeating itself knowing the cause and effect of people's actions. Perhaps the whole point was to show that history can not be changed (both philosophically speaking and of course in context of censors), but it is hard not to wonder if the future (and people) could have changed had certain things unfolded differently when Xiao Chu was 21 and 28. it was rather sad, for example, to see Yuchen deeply affected and changed because she misunderstood Mo An'an in their youth, and it was also frustrating to watch the young emperor so helpless against the misguided and villainous adults in his life.

Overall, a nice mini-drama if a conventional "happy ending" is not a requirement.