The Decagon House Murders

* Original
* Reprint
* English

* 1991
* 2007
* 2008
* 2017

* Old
* New

**The Decagon House Murders** (十角館(じゅっかくかん)の殺人(さつじん), *Jukkakukan no Satsujin*) is the debut novel of Yukito Ayatsuji, and the first volume of the House Series. A draft of the novel was originally submitted to the twenty-ninth Ranpo Edogawa Prize in 1983 under the title **Island of Remembrance** (追悼(ついとう)の島(しま), *Tsuitō no Shima*), but ultimately fell short. It was later published by Kodansha Novels with its updated title in 1987.

Although Souji Shimada's 1981 debut with The Tokyo Zodiac Murders is oftentimes credited as the first true shinhonkaku detective novel, The Decagon House Murders is widely given credit for launching the boom in shinhonkaku-style novels that came to dominate the 1990s. Many of the trademarks of the movement can first be seen in this particular title, such as metatextual references to classical detective fiction, as well as subtle nods to more contemporaneous writers.

## Synopsis

The plot is set in 1986, and follows a week long-camping expedition carried out by seven members of a certain university's mystery fiction club. They visit Tsunoshima, the site of a mysterious mass homicide and arson that took place the year prior. The island was at that time the property of eccentric architect Seiji Nakamura, who disappeared after the incident and left behind the bizarrely shaped building known as the Decagon House. The club members resolve themselves to spend a week in this house as they work on their own stories for the club magazine.

Meanwhile, on the mainland, Takaaki Kawaminami, an ex-member of the club, teams up with amateur sleuth Kiyoshi Shimada to unravel the original mystery of Tsunoshima. They wonder if there is any link between the mass homicide that took place in 1985, and the accidental death of fellow club member Chiori Nakamura—daughter of the same Seiji Nakamura that owned the island and built the Decagon House.

## Contents

* **Prologue** (プロローグ, *Purorōgu*)
* **Chapter One: First Day - Island** (第一章(だいいっしょう)　一日目(いちにちめ)・島(しま), *Dai Isshō Ichinichime Shima*)
* **Chapter Two: First Day - Mainland** (第二章(だいにしょう)　一日目(いちにちめ)・本土(ほんど), *Dai Nishō Ichinichime Hondo*)
* **Chapter Three: Second Day - Island** (第三章(だいさんしょう)　二日目(ふつかめ)・島(しま), *Dai Sanshō Fukkame Shima*)
* **Chapter Four: Second Day - Mainlad** (第四章(だいよんしょう)　二日目(ふつかめ)・本土(ほんど), *Dai Yonshō Fukkame Hondo*)
* **Chapter Five: Third Day - Island** (第五章(だいごしょう)　三日目(みっかめ)・島(しま), *Dai Goshō Mikkame Shima*)
* **Chapter Six: Third Day - Mainland** (第六章(だいろくしょう)　三日目(みっかめ)・本土(ほんど), *Dai Rokushō Mikkame Hondo*)
* **Chapter Seven: Fourth Day - Island** (第七章(だいななしょう)　四日目(よっかめ)・島(しま), *Dai Nanashō Yokkame Shima*)
* **Chapter Eight: Fourth Day - Mainland** (第八章(だいはちしょう)　四日目(よっかめ)・本土(ほんど), *Dai Hachishō Yokkame Hondo*)
* **Chapter Nine: Fifth Day** (第九章(だいきゅうしょう)　五日目(いつかめ), *Dai Kyūshō Itsukame*)
* **Chapter Ten: Sixth Day** (第十章(だいじゅうしょう)　六日目(むいかめ), *Dai Jūshō Muikame*)
* **Chapter Eleven: Seventh Day** (第十一章(だいじゅういっしょう)　七日目(なのかめ), *Dai Jūisshō Nanokame*)
* **Chapter Twelve: Eighth Day** (第十二章(だいじゅうにしょう)　八日目(ようかめ), *Dai Jūnishō Yōkame*)
* **Epilogue** (エピローグ, *Epirōgu*)

## Characters

* **K University Mystery Club** (Ｋ＊＊大学(だいがく)・推理小説研究会(すいりしょうせつけんきゅうかい), *K\*\* Daigaku Suiri Shousetsu Kenkyūkai*)**:** The main group of characters. Each member of the club is nicknamed after a famous mystery writer. Together, they visit Tsunoshima Island, the site of an infamous mass murder, in order to gather ideas for their own stories.
	+ **Poe** (ポウ, *Pō*)**:** A member of the mystery club. Nicknamed after Edgar Allan Poe.
	+ **Carr** (カー, *Kā*)**:** A member of the mystery club. Nicknamed after John Dickson Carr.
	+ **Ellery** (エラリイ, *Erarī*)**:** A member of the mystery club. Nicknamed after Ellery Queen.
	+ **Van** (ヴァン, *Van*)**:** A member of the mystery club. Nicknamed after S. S. Van Dine.
	+ **Agatha** (アガサ, *Agasa*)**:** A member of the mystery club. Nicknamed after Agatha Christie.
	+ **Orczy** (オルツィ, *Orutsi*)**:** A member of the mystery club. Nicknamed after Baroness Orczy.
	+ **Leroux** (ルルウ, *Rurū*)**:** A member of the mystery club. Nicknamed after Gaston Leroux.

Click "Show" to see all of the characters appearing in this book.

* **Seiji Nakamura** (中村(なかむら) 青司(せいじ), *Nakamura Seiji*)**:**
* **Kazue Nakamura** (中村(なかむら) 和枝(かずえ), *Nakamura Kazue*)**:**
* **Chiori Nakamura** (中村(なかむら) 千織(ちおり), *Nakamura Chiori*)**:**
* **Kitamura** (北村(きたむら), *Kitamura*)**:**
* **Seiichi Yoshikawa** (吉川(よしかわ) 誠一(せいいち), *Yoshikawa Seiichi*)**:**

* **Kiyoshi Shimada** (島田(しまだ) 潔(きよし), *Shimada Kiyoshi*)**:**
* **Takaaki Kawaminami** (江南(かわみなみ) 孝明(たかあき), *Kawaminami Takaaki*)**:**
* **Kyouichi Morisu** (守須(もりす) 恭一(きょういち), *Morisu Kyōichi*)**:**
* **Koujirou Nakamura** (中村(なかむら) 紅次郎(こうじろう), *Nakamura Kōjirō*)**:**
* **Masako Yoshikawa** (吉川(よしかわ) 政子(まさこ), *Yoshikawa Masako*)**:**

## Genre & Style

The basic setup of The Decagon House Murders is a deliberate pastiche of the highest selling mystery novel of all time, Agatha Christie's own murder on an island classic And Then There Were None.

## References

1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 The Decagon House Murders (in Japanese). Published by Kodansha.
2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 The Decagon House Murders (in Japanese). Published by Kodansha.
3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 The Decagon House Murders (Shinsho Corrected Version) (in Japanese). Published by Kodansha.
4. ↑ 4.0 4.1 4.2 4.3 4.4 4.5 The Decagon House Murders (in Japanese). Published by Kodansha.
5. ↑ 5.0 5.1 5.2 5.3 5.4 5.5 The Decagon House Murders Collector's Edition (in Japanese). Published by Kodansha.
6. ↑ 6.0 6.1 6.2 6.3 6.4 The Decagon House Murders (in English). Published by Locked Room International.
7. ↑ 7.0 7.1 7.2 7.3 7.4 The Decagon House Murders (in English). Published by Pushkin Vertigo.