Welcome back to another Japanese murder mystery book review. Yukito Ayatsuji’s mansion house murder series kicks off with The Decagon House Murders. The book was first published in 1987 and was translated into English in 2015 by Ho-Ling Wong.

I landed on this book after I read Uketsu’s books, Strange Houses and Strange Pictures. I mean, maps, gruesome murders and unlikely suspects? This was right up my alley.

A university mystery club takes an excursion to the island of Tsunojima which was a site of ghastly murders six months before. A decagonal house stands in the middle of all the mystery and the mystery writer students are to stay in that same house. The main house, Blue House, burned down in a fire from the initial murders. This macabre vacation takes a darker turn as the students are picked off one by one over course of their week-long stay on the island.

It is a locked room mystery that harks back to the Golden Age of mystery writers. The seven university students are referred to by their nicknames that are based on famous Western mystery writers — Ellery, Agatha, Poe, Orczy, Carr, Van and Leroux. This use of nicknames is used as a key device in the mystery.

I am pretty smug about seeing twists coming from a mile away in the plot but this one had me guessing right up to the very end. Especially that ending had me sitting up and gasping. If that doesn’t recommend this book to you, I have no idea how else to convince you.

The why of all the murders keeps the readers guessing from one lead to another. This remote island location is key in the mystery as well. The houses built there were designed by the architect, Nakamura Seiji, the prime suspect of the initial murders. The eminent architect is famous for designing trick houses with gimmicks in them.

Former club member Kawaminami takes an interest in the trip and the perceived danger once he receives a letter accusing the club member of murdering Chiori, another member of the club. The island serves as the perfect isolated setting without communication and electricity to set up the murders. The amateur mystery writers think they have a shot at figuring out who the murderer is and the prime suspect is Nakamura Seiji himself.

We are introduced to Shimada who has a legitimate shot at cracking the case as he lends Kawaminami a hand and they track down leads on the mainland. But the puzzle involves a convoluted murder plot that is not easy to guess at from the mainland. They think the tragedies and the culprit are contained within the bounds of the isolated island, but the truth is far from it. It takes looking into the first death of Chiori to figure this series of deaths out.

I was pleasantly surprised by the breathless plot that hooked me from the get-go. I am looking forward to reading the rest of the books in the series and heavily recommend Yukito’s works for all Japanese murder mystery aficionados.

You can grab your copy of The Decagon House Murders by Yukito Ayatsuji here.

(I earn a small commission from every qualified purchase from the link to continue reading and reviewing)

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Have you read The Decagon House Murders yet? Or any other works by Yukito Ayatsuji? What are your thoughts on them?

Feel free to drop a comment or reach out to me across social media at @thecalcuttanbibliophile. I would love to hear from you.