pedestrienne

While I always feel disdain when an author deliberately hides information so that it can be a twist when it should have really been part of the story, the strength of the weirdness of the curse was strong enough through the whole book so that the reveal didn't ruin it. It made it less powerful and I think Ayatsuji relies on this (it is in the 2 books I've read of his) when he is a good enough writer that he doesn't need to.

Also these kids and adults are so concerned with being polite that they make it harder to solve the mystery because they won't fully talk to each other, it's kind of hilarious.