Looking for manga like Boku Dake ga Inai Machi

So I recently have started to look for manga that are somewhat simmilar to Boku Dake ga Inai Machi, for those who do not know the series I'll also listwhat I liked about the series, wich is the criteria for mangas I'm looking for:
- Obviously it shouldn't drag on
- Preferable if it's already finished, though I'm not averse to ongoing series.
- It should preferably involve supernatural elements, like the time travel mechanic in Boku Dake ga Inai Machi, but it doesn't have to necessarily be time travel, it could be any supernatural gimmick.
- Romance is prefered, though I'm also not against manga without romantic themes.
- There has to be a central mistery that is the driving force for the manga.
- The prefered demographic is seinen, though if you consider the series is good enough it can even be shounen or whatever genre
I know the criteria is somewhat specific, but I trust people here will be able to suggest something worthy :heh:
Thanks in advance for all and any replies

Looking for manga like Boku Dake ga Inai Machi