Mimi (2014)

Both are bittersweet school love stories with a similar atmosphere.

Both Travel back in time for their First Love with similar vibes but Mimi is a little darker though

Es un mini dorama muy bonito, que puede gustarle a las personas que le gustaron Don't Worry, it's a Ghost.

One is a Korean mini series and one is a Hong Kong series. HM reminded me a lot of Mimi, though I preferred Hello Misfortune a lot more.
- Mimi and HM have very different vibes, Mimi is more sad overall, and only focused on the main leads whilst HM does focus a lot on the side characters.
- The FL is dead in both dramas and she is a ghost (and has been dead for several years) following the ML (for different reasons) even though she's not really suppose to.
- In Mimi the ML doesn't remember the FL whilst in Hello Misfortune the FL doesn't remember the ML, for supernatural memory loss reasons.
- Both ML's blame themselves for the FL's death.
- Both ML's liked the FL before her death (this is hinted at in HM).
- Both dramas have a SFL that in Mimi does end up with the ML whilst in HM, seems very likely to (but does not) end up with the ML.
- HM had an open, happy ending, whilst Mimi had a (to me) sad, bittersweet ending, one I hated.

It has a similar concept.
Both are short dramas with ghost, though Girl of 0AM is lighter/happier than Mimi, which is a lot sadder..