We should have more murder mysteries set in pyramids...
Kyuujou City is a small rural town, which is effectively run by the Ooki family. The wealthy family owns several enterprises located in the city, thus providing work for a large share of the population, but they are best known for the Ooki General Hospital, a large medical complex specializing in psychiatry. Its symbol is the Pyramid, a eight-storey high building that functions as the main hospital building, housing the psychiatric ward. The building consists of seven floors that form a stepped pyramid, with an open ceiling section at the center of the building. On top of the seventh floor stands a steel pyramid construction, from a smaller pyramid is suspended above the open ceiling of the floors below: this "eighth" floor is the private residence of Ooki Kimihiro, doctor at the hospital and the only son of Ooki Youta, the current director of the hospital, and his wife Ooki Nagi, who researches anti-aging technology at the hospital. This eighth floor is not built directly on top of the floor below, but being suspended as an anti-earthquake measure and was designed by Kimihiro's mother Nagi, who also has a degree in architecture and it was she who created the base design of the pyramid. The ground floor of the Pyramid has a two-meter high Pyramid model in a glass case, right at the center of the Pyramid: Ooki Youta believes in so-called Pyramid Power and once in a while, he prays to the model to enhance himself with Pyramid Power. Regardless of whether the pyramid truly provides him with power or not, the pyramid has managed to stand in Kyuujou City for nearly four decades, a sign of the Ooki's hold on the city.
While the Pyramid still stands strong, some of the other buildings on the complex are growing too old, so they will be demolished and replaced. Ooki Nagi has made designs for the new building, but she needs more dedicated architects to fill in the details and overlook the construction, and through a mutual acquaintance, Kumode and Miyamura of the Kumode & Miyamura Architecture and Detective Bureau end up with this assignment. They work together with Tobuta Constructions, the construction company that has built all of the Ooki-related buildings. There is a joint meeting between the hospital people, the foreman of Tobuta Constructions and Kumoda and Miyamura at the Pyramid to discuss the upcoming plans. Kumoda sends a drone out to scope the land, and can't help but take a look at the top-floor of the Pyramid, where he sees Ooki Kimihiro having a row with his mother Nagi, after which he retreats to his private quarters (the suspended pyramid above the main pyramid), locking the door behind him. Some time later, Kumode and Miyamura are ready to get started on their work while the others too prepare to leave the pyramid, when suddenly... the suspended pyramid comes falling down the open ceiling, landing with a crash on the pyramid model on the ground floor. The private quarters of Kimihiro are completely destroyed and among the rubble, Kumode discovers Kimihiro, who is not only heavily injured from the fall down and being crushed by the building... he's also been stabbed with a knife! A sickly slender elderly man is also found among the rubble, who appears to be the man who stabbed Kimihiro, but how did he get in Kimihiro's (locked) room to stab him, and why did the pyramid room come falling down? That is only one of the many riddles Kumode faces in Monzen Noriyuki's latest novel Nezumi to Kirin no Pyramid ("The Pyramid of the Mouse and the Giraffe", 2025).
Monzen's latest book opens with crazy diagrams for the Pyramid, a building which in a way symbolizes this story perfectly. On one hand, in real-life, nobody is going to build a gigantic stepped pyramid as the main building of a hospital, nor is anyone going to design that building so the top floor/pyramid is suspended from a metal construction above the rest of the pyramid. It's fantastical and only created like that to act as the setting for a mystery story, and that's great! But not realistic at all of course. But Monzen studied architecture, and realism in that regards is an important aspect of this books, so we have this unrealistic, fanciful, over-the-top building, which at the same time is designed realistically, with Monzen giving exact dimensions and the reader being given explanations of how the weight-baring is done and other things that need to be considered like patient safety, window regulations and how for example what the measures are to prevent rain/other downfall from entering the hospital via the open ceiling. The Pyramid of the Mouse and the Giraffe is honkaku mystery featuring a strange building at its most bizarre, but also its most realistic.
The book opens with the top pyramid come crashing down and the discovery of the stabbed Kimihiro and the unknown elderly man among the rubble, which Kumode soon declares a locked room mystery, because he saw Kimihiro enter and lock his private quarters via his drone, and the elderly man was definitely not inside those quarters at that moment. The book then jumps a few days back in time, where we follow Hotta, the foreman of Tobuta Constructions, as he meets a homeless elderly man living on grounds owned by the hospital. Hotta needs the man to move as they will be using this part as a supply road, but as the two men talk, Hotta becomes interested in this man he calls Mori. Mori turns out to have lived for thirty years at the Ooki General Hospital. He had been held as a mental patient, but Mori swears there was nothing wrong with him: he was just kept captured in the hospital, with his brother (who needed him out of the way) only paying the hospital to keep him there. After twenty years, Mori was 'basically' released, but as he had no money, skills or connections, all he could do was remain at the hospital doing odd jobs. Eventually though, he was completely released, leaving him no choice but to live as a homeless near the hospital. Mori reveals more of the dark history of the Ooki General Hospital to Hotta, how they often put patients in "isolation chambers" in one of the old buildings that is slated to be demolished now. Patients were tied down to concrete slabs and had to go without food for a whole day to "calm them strangle yourself/hang yourself, but the room itself was of course also locked from the outside. Hotta himself also knows of another incident that occured at the hospital that happened prior to this locked room mystery, when someone broke the glass case of the pyramid model: nurses came checking out what had happened as soon as they heard the glass break, but they found the pyramid model gone. But how could someone steal a two-meter high pyramid in mere seconds and leave without leaving a trace? The front door was found open, but the only footprints found outside in the snow belonged to a cat, and it surely wasn't a cat who did it, right?
While Nezumi to Kirin no Pyramid thus starts right off with presenting the main mystery, the flashback to the days before the crash introduce more mysteries that occured several decades ago at the hospital: a locked room murder of a patient in an isolation chamber, and the incredible theft of the pyramid model. There are more mysteries beyond these, like Kumode being intrigued by the strange family sigils found on Nagi's clothes, the mystery of Mori's true identity and whether he's telling Hotta the truth or not, letters supposedly from patients who are being kept in the hospital against their will and more of that. Again, we have here parts that feel part fantasy, and part very realistic. The parts about people being held in the psychiatric ward for decades and eventually losing any reason for wanting to leave (because there's no way to survive on their own after being isolated from the outside world for so long) are creepily realistic, while at the same time, we get an ending where Kumode suggests some of the stories we were told might have been fictional creations by people who are indeed suffering from a mental disease. Because a lot of the mysteries in this story took place several decades ago, Kumode admits it's impossible to find evidence for some of the theories he proposes, but those theories are incredibly weird at times and in a way, honkaku mystery at their best and worst (fantastical solution that is in no way feasible or remotely realistic), so there's always this clash between the fantastical and the realistic throughout the book. This is the most apparent in the mystery of the locked room murder in the isolation chamber about three decades ago: the description of the isolation chamber is horrific and also eerily real, with people being basically tortured there to lose all hope and to basically force them into becoming mentally unstable, while the solution suggested by Kumode is just crazy in terms of how unrealistic it would be. And at the same time, it has some brilliant moments, for example as to how the murder weapon would be disposed of. Kumode later on suggests a different solution that might be as viable as his 'main' one, which is more realistic perhaps, but also just less fun.
The mystery of the stolen model of the pyramid is also a good example of the realism clashing with the fanciful: the idea of how and why the model was stolen is good and just what you want to see in a mystery novel, but Monzen presents its very realistically, showing calculation of certain objects to show how it could actually work, when in most mystery novels you'd just get an explanation and you'd nod, instead of going through all the numbers to make sure it actually works. The way how one hint connects to the isolation chamber murder later on is great though.
And then we come to the main mystery, of Kimihiro being found dead and stabbed in the remnants of the suspended pyramid after it came crashing down seven floors. The locked room aspect of this mystery is surprisingly simple and to be honest, not very impressive: it's basically a variant on one of the oldest tricks, only with a 'grand' presentation due to the pyramid setting. The how behind the crashing pyramid and especially the why though, are fantastic. The whole motive behind the murder is absolutely stunning and genuinely insane. I think the motive could've been worked out better by doing a more robust set-up for the reveal, but the idea itself is one of those motives you'll keep in mind for a loooong time after reading the book. The way it ties back to the fantastical setting of the Pyramid hospital building is impressive too, and on the whole, you do feel this is something perhaps only Monzen could pull off due to his focus on actual buildings. This is definitely the part that makes the book worth reading.
I do think the book could've been longer to flesh out some of the better aspects of the book.As it is now, I feel some important moments just lack the proper build-up and at times, the book borders on the unfair when it comes to it being a mystery novel: more pages would have definitely helped making feel the overall picture more consistent and connected. As it is now, some of the important elements feel like they just suddenly appear to take the main spotlight and it makes the book feel uneven. The book features a recommendation by Nikaidou Reito, and it almost makes me wonder how this story would've been if the two authors had worked together, as a lot of elements in Nezumi to Kirin no Pyramid I can also see working in Nikaidou's style for the earlier Ranko novels. The story is wrapped in a way I have also seen in Nikaidou novels, with a hint of fantasy, which at one hand feels like it should clash with Monzen's style, but I guess having a setting like a mental hospital helps out a bit.
Overall though, I think Nezumi to Kirin no Pyramid was a worthwile read, even if there are definitely elements I feel are underdeveloped or not connected well enough to the main narrative yet. At the same time, I enjoy the core mystery plot and the ideas shown there, and the main motive that drives this mystery is just amazing and probably one that I will remember for a long time.










