Certainly more than the plot itself, the problem I have was due to the overhype around it. Because of the circumstances of its emmission, many classified it as "the true anime of the year", a hidden gem that went unnoticed because of a certain evil organization with big mouse ears.
But the truth is it's good yeah... but it's not that special.
The animation is pretty good and the music slaps sometimes, yeah, but the plot that should be the most important thing on a mistery story and that has been compared (not without reason) with ReZero or Steins;Gate is far below the quality of those. With an argumet that asks you to suspend your disbelief from the beginning and whose protagonists alternate between smart and dumb depending on what the story requires; not to mention several deus-ex machina, "justified" during subsequent flashbacks for the shock value.
(As an example and to minimize spoilers I will only say that the protagonist returns to his old house for the funeral of a friend -who died just a couple of days ago- however there are very few people who really show mourning and those who do, seem to forget it completely as the story progresses, giving more importance to their love relationships... and mind you, on a mistery story, those personality changes should not go unnoticed.)
In the end, it's a good series, and as I said, really my problem is that I was expecting to see a masterpiece worthy of being in the best anime of all time, but in the end it's just.... good; and that's kind of disappointing.
