Girl of 0AM (2015)

Both are 'YG-dramas', with Winner (NTH was a member of Winner) members as male leads. Both are short, so it's easy to watch it 'at once'.
Both have a mystery which is hidden by female lead.

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..