「探偵って、そういうものなんじゃないのかな?少なくとも僕はそう思っているよ。探偵とは、大多数の人間を納得させて、事件を終わらせる存在だよ」
『異世界の名探偵 1 首なし姫殺人事件』
"Isn't that exactly what a detective is though? A detective is someone who can convince the majority of the people and bring an end to a case"
"The Great Detective of the Other World 1: The Case of the Headless Princess"
If you have been following anime these last few years, there's no way you could've avoided the word isekai. Literally, isekai means "a different world" but it is commonly used to refer to a certain subgenre in Japanese popular fiction. In an isekai series, the protagonist is usually a person from Earth who ends up in a different world (usually a fantasy world) by means of transportation, reincarnation or some other manner. The genre often involves some kind of power fantasy, with the very ordinary human using their memories/knowledge from Earth to their advantage in their new situation/the other world to become the legendary hero/evil overlord/whatever the story is about.The genre has parallels with classic literature like Alice in Wonderland and The Chronicles of Narnia of course, but it's been especially popular in Japan the last couple of years, with an unbelievable amount of light novels, manga and anime released based on this concept, but all with slightly different takes and also far too literal titles that explain the whole premise like In Another World With My Smartphone or That Time I Got Reincarnated As A Slime.
And of course, it isn't strange that there's also an isekai mystery novel. Katazato Kamome's Isekai no Meitantei 1 - Kubinashi Hime Satsujin Jiken ("The Great Detective of the Other World 1: The Case of the Headless Princess", 2019) was originally published with the title Fantasy ni Okeru Meitantei no Hitsuyousei ("The Necessity of a Great Detective in Fantasy") on the website Shousetsuka ni Narou, where users can upload their own fiction and have other users read them. The story starts in a very, very familiar manner when it comes to isekai works. Our protagonist is an ex-cop who had always dreamt of being like the detective from the novels, but it was only in his dying moments, stabbed for some insignificant reason, that he realized that the great detective is not of this world anymore. To his great surprise though, his dying moments are followed by his own birth scene. While completely confused at first, our protagonist realizes he has been reincarnated as a baby now, but still in possession of his old memories. What's equally surprising is that he is not in Kansas anymore, or even Earth. He finds himself reincarnated in Pangea, best described as the world from fantasy novels, with magic, elves, dragons and more. Our baby protagonist is given the name Van and he grows up as the eldest son of a peasant farmer family. Van turns out to be a rather talented student, especially of magic: magic is a skill most people master in this world up to a certain degree, but usually at a rather limited scale. Van's memories of Earth science give him an edge in his studies however, and realizing how talented their son is, his parents decide to send him to the Royal Academy of the kingdom of Sherck. While normally only reserved for children of nobility, the commoner Van is chosen as this year's scholarship student because of his enormous skill in magic, and he soon becomes friends with two other 'outsiders': Leo Bahl is the brash, but clever young head of one of the most important families of nobility of Sherck, while Kirio Lafla is the only daughter of an impoverished family of nobility who was raised as a boy. Eventually, all three friends manage to graduate from the academy, and the joint thesis of Leo and Van on a complete restructuring of the justice system in Sherk, emphasizing the need for scientific investigation, attracted attention from the whole country.
Each year, the top graduating students are commemorated in a Commendation Ceremony, but this year's ceremony is exceptional, as it will be attended by the king and queen of Sherck, as well as their daugther Princess Victi, who is considered to be the living reincarnation of Saint Phata, protector of the whole world of Pangea. Victi hardly appears before others, as the royal family and the church fight a political war over her, so the fact that Victi herself will speak to each of the four students individually is singularly unique. The private ceremony is held at the former Royal Academy, a small building with no windows originally built as a fort (because the students are usually of nobility). Princess Victi is to receive each of the students one after another in the chapel as part of the ceremony: her two security guards (one of the Royals, of the church) guide the students from the main building to the chapel and once the princess has spoken with the student, the guards bring the student back to their room. Each time the Mythril doors of the chapel are locked by the two special keys held by the two guards, meaning Princess Victi is always safe inside the chapel even when they are transporting the student to and from the chapel. After the last student's done, the guards walk the princess back to her room in the main building, when suddenly part of a wall is blown up, and in the confusion, the princess disappears. One of the chapel keys is stolen too, and when they blow open the Mythril doors of the chapel, they stumble upon a horrid sight: the decapitated body of Princess Victi, reincarnation of Saint Phata herself, lying on the floor! But how could her murderer have opened the chapel with only one key, and where did they escape to considering the whole forest surrounding the former Royal Academy is swarming with soldiers? The Royal Detective Geralt the Silent is soon called to explain the situation, butLeo and Van protest to his farfetched 'solution' and say they can really solve this mystery based on proper forensic investigation and logical reasoning.
Okay, so a detective novel in a fantasy setting, one where magic is possible. Like I mentioned in a short piece last year, I love mystery stories that make use of supernatural settings. As long as the 'unusual' elements are properly introduced and explained, science fiction and fantasy elements work perfectly fine in mystery novels (in fact, the best examples authors do their best to actually be more fair than most other mystery novels). Magic is fairly well defined in Isekai no Meitantei 1 with clear limitations: line of sight is for example essential to cast magic in this world (you can't cast magic in some remote place on the other side of the world), casting takes time and while a skilled magician can easily create a block of ice the size of a fist, no magician can conjure up a whole snowman out of nowhere (to people who know Fullmetal Alchemist, magic here kinda works like alchemy in FMA, in the sense that a scientific understanding of all elements help the magician cast their magic). The Challenge to the Reader too helps define some more limitations, and with a fair amount of text that help define what magic can and more importantly can't do in this world, I'd say that Isekai no Meitantei 1 is still a fair mystery novel, that can be solved by logic and reasoning, and definitely no less fair than something by Carr for example.
It does take a long while to get to the mystery plot though. The first half of the novel is really just set-up of the world, with Van adaptating to this new environment and explaining everything about Pangea to the reader. It's fairly standard isekai fantasy stuff, which also makes this part quite boring, as so much is just exposition. On the other hand, it's also necessary, as both Van and the reader need to learn what is exactly possible in this world in order to present a fair mystery plot. You also have the usual power fantasy tropes, with Van turning out to be a brilliant student due to his Earth memories, and even co-authoring an epoch-making thesis. In the early parts of the novel you might think you'll be getting some kind of Harry Potter story, but then it jumps a few years in time, and suddenly we have Van being some kind of brilliant philosopher who wishes to change the whole criminal justice system. By the way, there are official detectives in this world, but because here the natural sciences have not developed and due to the presence of magic, investigation work in Pangea is more like 'guesswork' and there's no need for gathering evidence, proving a hypothesis or even having someone check the detective's solution: usually people just accept whatever the detective says happened (and sometimes, the 'solution' is just "perhaps there's this obscure magic spell that could..."). It's Van's history as a cop and as a fan of Earth's mystery novels, that drives him to conduct investigation in the same manner as his beloved detectives. In a sense, this reminds of the 3DS game Professor Layton vs. Gyakuten Saiban, where medieval fantasy witch trials are shaken up by the introduction of.... logic in the trials.
When you make it to the main mystery plot, you get a well-executed, but perhaps also surprisingly unsurprising detective story involving magic. As mentioned, the effectiveness of magic in this world is fairly limited. For example, at a limited distance, throwing a knife is both more effective and faster than trying to cast an explosion spell at the target. In this mystery plot, magic is therefore used for smaller scale events, but it's definitely a plot that only works because of the existence of magic. What makes this novel 'unsuprising' is exactly the fact magic is mainly used for rather smaller parts of the crime, rather than something large-scale. Of course, that's also what makes Isekai no Meitantei 1 a fairly-clewed mystery in the first place, because magic is kept at a scale that is still comprehensible to the reader, and Katazato is sure to mention all the practical uses of magic as utilized in the actual crime, have already been properly mentioned long before the solution. Magic is simply a tool like a string or a needle, not the solution to everything. Whereas Geralt the Silent first proposes a solution that is quite ridiculous for a mystery novel ("and then the murderer used some unknown magic spell that..."), the solution Van arrives at is one the reader can deduce themselves based on the clues, based on a logical examination of everything presented to them. I do think it's kinda easy to guess who the murderer is, because so much of the plot depends on a certain fact, but overall, it's a competently clewed mystery that uses magic at the right places.
Considering the current release now has a "1" in its title, I assume sequels to Isekai no Meitantei 1 - Kubinashi Hime Satsujin Jiken will follow. And yes, I'd be interested in more adventures of Van in Pangea. I do think the question of whether this really needed to be an isekai story is a fair one. At this point, Van having memories of his Earth life is mostly manifested in the fact that he's a quick learner, and the fact he knows about scientific investigation and mystery novels in general, but to be honest, this could've been a pure fantasy novel too, with Van simply being a bright kid who noticed the shortcomings of the investigative methods in this world. At the moment, there's little that really necessitates Van being from our world, besides being a vehicle for the reader to help introduce the world and provide for a framework for a fair mystery story, but Van being an Earthling isn't really interfering either, and perhaps we'll see more of that part of his Earth past in future volumes. As a first step in the world of Pangea, I'd say this first novel does a perfectly fine job.
Original Japanese title(s): 片里鴎『異世界の名探偵 1 首なし姫殺人事件』