I believe that for a good mystery to be well told, the author needs to know how to "cook" the reader, and this manga knows perfectly well.
The beginning is impressive due to the author's ability to pace responses while adding layers of mystery.
Another important point, the art of this manga is very different and they compose very beautiful and impactful pictures.
Another merit is the ability to use cliffhangers in a way that encourages you to consume more of the story, while not getting tired due to the exhaustion of using it.
As I said, you need to know how to "cook" and that includes knowing how not to overdo it.
Finally, a really captivating suspense manga. I recommend giving it a try.
