Naoyuki Uchida under the pen name, Yukito Ayatsuji, had taken classic locked room mysteries to the next level. You can never predict who the perpetrator is and what their motive was.

Yukito Ayatsuji is a Japanese writer of mystery and horror. He is one of the founders of Honkaku Mystery Writers Club of Japan, a club where its members write honkaku, and one of the representative writers of the new traditionalist movement in Japanese mystery writing.

The Decagon House Murders starts with a number of # university kids involved in a mystery club visiting a “haunted” island where a mysterious cold case had occurred. Their motive is to inspire themselves to write more books for their club based on the case. The island inhabits peculiar homes made by an architect named Nakamura Seiji. These buildings were odd as they stuck to a particular theme. The Blue Mansion was embellished entirely in blue, while the Decagon House was made in the shape of decagon (even the cups!). Unfortunately, the Blue Mansion had been burnt down, so the students were left to reside in the Decagon House for a week, with no contact as it was an isolated island, plus they could not leave without a boat, making their situation “locked” (hence the “locked room mysteries”). During their trip, a few people (Kawaminami, Morisu, and Shimada Kiyoshi), also associated with the club (past and presently) are being sent threats from Nakamura Seiji and are investigating why and how this could happen, as Nakumura is dead.

The Mill House Murders begins with an interesting and rich person named Fujinuma Kiichi. He is the son of a renowned painter, Fujinuma Issei. Once a year, four guests can visit the secluded Mill House where Kiichi and his father’s valuable paintings lives. These guests are allowed to come to such an isolated place because of what they’ve done for the Fujinuma family. The first guest, Oshi Genzo, is an art dealer, the second guest, Mori Shigehiko, is a professor at an art university. The third guest is Mitamura Noriyuki, a director of surgical hospital, whose father had performed lifesaving surgery on Kiichi as he had been in a terrible and life-threatening car accident. Lastly, the fourth guest, Furukawa Tsunehito, the deputy priest of Fujinuma’s family temple. One year, something gruesome and unfortunate happens. Two people are murdered, and one is missing. Negishi Fumie and Masaki Shingo (a friend of Kiichi and driver of the unfortunate car) have been murdered. A servant and a friend of Kiichi. Furukawa Tsunehito is declared missing and the possible suspect of murder.

The cold case began when the Blue Mansion burnt down while injured people were inside, making it murder and arson. The people who died in it were: Nakamura Seiji, his wife, two servants (couple), and a missing gardener; the prime suspect of this crime as the police can’t find logical reasons to indicate otherwise. The casualties suffered to these people beforehand were: the servants’ heads were bashed in, the wife was strangled to death, had been thought to be sexually assaulted before murdered, plus her left hand went missing. Nakamura himself was doused in kerosene. They also all had a presence of sleeping drugs in them.

Fujinuma Kiichi awkwardly invites the same people over again while missing the two people, Furukawa and Masaki Shingo. The feeling is eerie and mysterious as the same weather from last year reoccurs and is making everyone uneasy, thinking the same events will happen again, but this time there is an anomaly. Shimada Kiyoshi. For some reason, that Kiichi himself didn’t even understand, he allowed Shimada to join the annual tour. Shimada had appeared as he wanted to investigate the murder from last year and was drawn to it because Nakamura Seiji had built the Mill House. After everyone settles in, another murder had occurred.

I would recommend these books to people who enjoy murder mysteries and like to solve the case as it goes on, because these books will definitely test that and will shock you when you get the answer. Coming from someone who reads many classics like this, I could have never guessed the ending. A downside is that names are read backwards as this is a Japanese book and in Japan people introduce themselves last name, then first. For example, people would read my name as, Herbert Makana. This attribute makes the book hard to follow, especially in The Decagon House Murders as the university students also have code/nicknames for each other that they mention very often, making it hard to keep track of who is who. Luckily, The Mill House Murders comes with a character sheet in the first few pages of the book. My favorite trait of the books is that they include blueprints of the house which helps if you’re trying to solve the mystery for yourself. My favorite character would have to be Shimada Kiyoshi, as he’s very intuitive and smart, and I like these books because of these impossible mysteries, but logical explanations. If you’re going to read these books, read The Decagon Murders first, then The Mill House Murders as you’ll have to understand the context from the first book to further comprehend the second. Additionally, there’s also more books written by Ayatsuji such as The Labyrinth House Murders.