Both dramas feature time travel bringing the leads together, and an open, ambiguous, but hopeful ending (nearly identical).

While completely different in plot and setting, there are some interesting similarities. Both FLs end up in a "different world" (traveling in time vs. entering a shadowy world of assassins) where they meet the ML. Both MLs are played by the same actor, and are both kind and quiet characters. Both dramas feature a focus on umbrellas and have a more unique tone and "look". The endings of both, and the ML's fate is open-ended and ambiguous but hopeful.

School setting, sweet relationship between leads, ML is a good student and tutoring FL who is a poorer student. Their personalities are somewhat similar.

Both feature time slip time travel where ML and FL can travel to each other's time, subtly influencing and changing events.

Short length dramas (film vs. short series) featuring a love story, time travel, and changing fate.
............................................

Short length (film vs. short drama) love stories where the main couple are brought together by time travel, and changing past events.

Both are short (film vs. movie length) dramas featuring time travel, and changing past events for the future. Both have open, but satisfying endings.

Both are Chinese dramas with a love story based upon time travel and changing fate.
..................................

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.

Both are short dramas involving time travelers trying to save a life/lives. Both have unexpected twists.

Both dramas involve time travel and trying to change fate to prevent death(s). Both have a subtle romance between the main couple.

FL time travels and returns to her younger self and falls in love with the ML. Both FLs then try to undo a death (FL's mother vs. ML's). Both are school setting. The FL has met the ML in the past but doesn't know/remember it until much later after she time travels.