I read this in one day as part of a 24 readathon (a few words on that: I feel like I haven't read much so far, but the night is youngish?). It was a really fun mystery to mull over the course of the day.

The Tokyo Zodiac Murders is written as a very classic mystery novel - we go through the clues, through false theories, and the waters gets very very murky before they get clear. The author inserts himself in the story twice to encourage you to solve the mystery yourself. I didn't do this because I'm pretty terrible at it, but I appreciated the clever ways in which the narrative was broken up with these or other "intermissions". The ending was also satisfying, which is pretty important in a pure mystery novel.

Recommended if you like classic detective stories aka Sherlock Holmes, want to try solving the mystery yourself, and think math and astrology are both pretty neat.

More thoughts here: https://youtu.be/N3d0uvty-uQ