The first book's concept is very similar to a standard mystery novel, and is executed very well. It just allows you to work things out enough that you can piece together clues and figure out flaws within character logic. However, it will be impossible for you to work out what actually happens unless you are an ace detective.
The main character- Ii-chan plays the role of Watson in the novel. He isn't really solving the mystery completely and is only filling in gaps in what actually happens. This of course means the reader is also left unaware of what is truly going on until the very end, where the character that has been foreshadowed all along to be an ace detective finally shows up and results in some great interaction between the main character and them.
The cast of characters is absolutely great, each have their own nuances and are clearly defined in a short space of time. One of my favourites is the mind reader character. She has some of the best interaction with the main character and sets up the second novel. Pretty much all the interactions between her and Ii-chan is a build up and foreshadows the events of the next book and the rest of the series.
It's a murder mystery that's well executed, I can't describe it due to spoilers though.
The second book is where is picks up immensely. Ii-chan's character is so clearly defined here that he no longer becomes a viewpoint for the reader but an unreliable narrator for the story. The characters that are introduced in this book are very interesting, and 2 of them are actually quite strange complex characters on the inside but aren't elaborated on for reasons.
The the second book is better than the first and slowly bridges the way out of the mystery novel genre and into something new in the third book.
I highly recommend this series. Currently 2 books have been published in the west and the rest are being fan translated.
