A review by eudaemonics
The Decagon House Murders by Yukito Ayatsuji

adventurous dark mysterious tense medium-paced
  • Plot- or character-driven? Plot
  • Strong character development? No
  • Loveable characters? It's complicated
  • Diverse cast of characters? No
  • Flaws of characters a main focus? Yes

5.0

I actually started reading this book after finishing Umineko no Naku Koro ni. I knew from a playthrough that this was one of the key inspirations, especially as a shin honkaku defining piece, but boy did I not expect it to smack me in the face with familiar plot devices right in the prologue that Ryukishi07 paid homage to.

The prose and character writing is nothing to write home about. It's very formulaic. I found the true genius of the work to be the structuring of the murders, puzzles, and how fair play it was while still subverting a seasoned reader's expectations by bending but playing within certain mystery novel rules (Van Dine's in particular).
While I agree that the characters were robotic in nature and there was no time to get to know them, Ayatsuji successfully makes the culprit's confession stick the landing by carrying the momentum all the way to the implied divine retribution they eventually receive. I also personally just did not expect emotionally gripping character writing from this, I wanted a puzzle, and I got a puzzle.

Many of the strong scenes happen at the end of the novel, in my opinion. I can see why this is a genre-defining piece, but it also wears it's flaws proudly on it's sleeve.

SPOILERS BEGIN BELOW

I praise Ayatsuji for using a lot of meta elements that would not have worked if this was not a written work. The ultimate reveal of Van Dine as the culprit is simply perfect since we don't know much about what Morisu and Van look like besides a few descriptors.
The foreshadowing of Morisu = Van Dine was also genius, even if I never wrote it down, I took a mental note of Morisu's club name being kept from the reader even though he was actually a current member unlike Kawaminami/Conan.
My favorite part about this is the culprit having so much of an upper hand that both detectives, Conan and Ellery, actually failed to stop anything from happening and actually assisted in making the tragedy happen more cleanly and scapegoated Nakamura Seiji effectly. Of course, Shimada seemed to have been one step ahead, even if we'll never know what happened after the fact.

It's not a perfect novel, but I gave it 5/5 stars just because it was such a gripping read that I couldn't put it down, and I was impressed by the emotional scenes at the end, particularly Ellery and Van in the basement of the Decagon House and Morisu and Shimada discussing the truth of the serial murders. It's a great introduction to honkaku/shin honkaku and I hope more of Ayatsuji's house murders are translated into English in the future.