Tasogare Otome x Amnesia: Taima Otome

Some kind of romantic relationship between human and non-human (yokai, vampire, ghost, alien, ...)

Anime specializing in various supernatural and paranormal tropes, usually with mystery and investigation underlying. This stack places weight on the more spiritually focussed paranormal anime.

As in, this isnt just anime with ghosts. There's usually a deeper grasp of the details around the paranormal displayed in these anime that present more compelling and believable paranormal themes. Some that are on here are spiritual in a more personal sense, that they stimulate your spirit in a deep way, not always that the anime itself has spirits.

But energies / ghosts / spirits / yokai are usually present. Based on whether the anime left an intellectual impression or not, some may think the anime on here aren't worth it if you're not in an open mind.

Animes with the horror, paranormal and supernatural genres.

Quite the long title eh? Well, but the statement is true. Most of the times anime on MAL ends up in 6.5 rating category just because there is nothing to spice up the "unique isekai idea" for the 999th time. Of course with proper atmosphere that might as well not be needed, or when you try to send a message of sorts. But even so, you might've not realised it but it's quite popular to insert some subplot notes of romance in the background for those who wish to find that. Even anime like frieren have veeery faint but still apparent romance subplot that does not interfere with the idea of adventure by any means.

Alright now that you've A ignored allat yap above or B carefully read sentence by sentence, we can come to the reason of this stack - above average anime that has AT LEAST faint notes of romance in them ( enough for enthusiasts to enjoy ) that COULD be worth spending time on AND you might've accidentally skipped past.

Also I give comments on few confusing ones if you perhaps couldn't find the "romance" part.