The Decagon House Murders

The Decagon House Murders follows seven members of a university mystery club who travel to Tsunojima Island for a week-long stay. The island was the site of multiple unsolved murders six months prior, when the owner, his wife, and their staff were killed. On the mainland, a former club member receives an accusatory letter about a student's death at a past club gathering. The letter connects to the island murders and suggests darker forces at work. A parallel investigation begins as more similar letters surface. The novel operates as both homage to and reinvention of Agatha Christie's And Then There Were None, explicitly acknowledged by the characters themselves. The story alternates between events on the island and the mainland investigation. The book exemplifies the "closed circle" mystery format while exploring themes of guilt, justice, and the gap between fictional detective stories and real-world violence.

Readers note strong parallels to Agatha Christie's "And Then There Were None," with many appreciating the distinctly Japanese take on the classic locked-room mystery format. Liked: - Complex puzzle structure that rewards careful reading - Atmospheric island setting - Dual storyline structure - Translation quality - References to classic mystery fiction Disliked: - Character development lacks depth - Some plot points require knowledge of Japanese culture/language - Middle section pacing slows - Ending feels rushed to some readers - Character names can be confusing to track Reader Scott on Goodreads: "The architectural metaphors add an extra layer of intrigue to the mystery." Ratings: Goodreads: 3.8/5 (2,800+ ratings) Amazon: 4.3/5 (450+ ratings) LibraryThing: 3.9/5 (200+ ratings) Several reviewers mention it works better as a pure puzzle mystery than a character-driven novel, with one Amazon reviewer noting: "Come for the clever plotting, not for deep character studies."

And Then There Were None by Agatha Christie Ten strangers trapped on an isolated island face death one by one in this locked-room mystery that inspired many closed-circle murder stories.

The Tokyo Zodiac Murders by Soji Shimada A detective investigates an unsolved mass murder case from 1936 involving cryptic zodiac messages and locked-room killings.

The Murder of Roger Ackroyd by Agatha Christie A country doctor narrates the investigation of a murder in a closed community where every resident has secrets to hide.

Death in the House of Rain by Szu-Yen Lin Students gather in an architecturally distinctive house where murders occur during a rainstorm, trapping them with the killer.

The 8 Mansion Murders by Takemaru Abiko A detective must solve seemingly impossible murders in an oddly-constructed mansion with a distinctive figure-eight layout.

🔍 The book popularized the shin honkaku (new orthodox) movement in Japanese mystery fiction, which aimed to return to the complex puzzle-solving aspects of Golden Age detective stories. 🏛️ The Decagon House's unique architectural design was inspired by real-life buildings created by modernist architect Claude Parent, known for his theory of "oblique architecture." 📚 First published in 1987, this was Yukito Ayatsuji's debut novel, written while he was still a student at Kyoto University where he was a member of a mystery fiction club similar to the one in the book. 🌊 The novel pays homage to Agatha Christie's "And Then There Were None," sharing similar themes of isolation and a dwindling group of people trapped on an island. 🎭 Each of the seven student characters uses a pen name taken from famous mystery writers, including Van Dine, Carr, and Leroux, adding a meta-literary layer to the story.