As a BL it is a beautiful romance. BOTH ARE ALIVE and human. Don't let the poor synopsis throw you. Think of it as a BL set against the backdrop of here being ghosts. The boys set out to help unravel a mystery about a ghost house in the town. And in the process, fall in love.
It doesn't have a lot of the dumb forced dramatic conflict you see in some shows. No pointless trouble for the sake of trouble. There is plenty of drama but it is a lot more grounded and real.
The main actors have chemistry and there is plenty of good skinship. Not a single dead fish kiss! Their handholding alone is more emotional and sexy than most stuff you find in a lot of BLs. (And you get a lot more than handholding - don't worry!)
The side characters are all enjoyable. If anything I am left wanting more of them! I wish the series were longer than 8 episodes.
The supernatural element has a little bit of scare/horror, but it isn't a dark show. If you scare easily, don't worry! Yes, you see ghosts. He's a ghost hunter. But he isn't going around vanquishing evil ghosts. He is hoping to meet then and communicate with them.
The pacing of the show is slow and steady. Some reviewers are frustrated by it. But it isn't constantly hitting you in the face with cheese and cliche. It allows the emotions to breathe. Some viewers just want brainless smut and comedy. Fine. that isn't this.
My only criticism is that it is too short. There are so many things (mysteries, side character relationships, and so on) that are hinted at or touched on that could each have been expanded to a full episode. The show could easily have been double in length. That isn't to say that it is missing something. Just that like with any really truly good story, it leaves you wanting more.