I recently finished reading Kie Hojo’s A Sweet Death for the Famous Detective, so this is a good chance to talk about setting-based mystery novels. In recent years, Japanese setting-based mystery has raised the banner of “rule innovation” and set off a frenzy where everything can be turned into a setting. From time loops to supernatural prophecies, from zombie sieges to AI solving cases, writers keep using imaginative frameworks to reconstruct the boundary of honkaku mystery. However, when I was reading Hojo’s A Sweet Death for the Famous Detective, I felt a fatigue caused by being backfired by “over-setting”. This work stacks VR games, double closed-circle mansions, Werewolf-style mechanics, interaction between real and virtual spaces, and other elements into a complicated maze, and in the end I got lost in the mud of rules. By contrast, Tomoyuki Shirai and Masahiro Imamura create astonishing tricks with “minimal rules”. This contrast made me reflect: maybe the appeal of setting-based mystery does not lie in how complex the rules are, but in how to use the fewest “bricks” to build the most exquisite “tower of logic”.
Main text (no spoilers)
The story of A Sweet Death for the Famous Detective is that Toma Kamo and Yuki Ryusen, the two protagonists from the author’s same series, accept an invitation from the developer of the VR game Mystery Creator, Megalodon Games, to attend a game trial event at Megalodon Villa on an isolated island. But before the game starts, everyone is told that the person most important to them has been taken hostage. To rescue their family and return safely, they must solve murders happening in both the real world and the VR world at the same time.
Before I started reading, I immediately thought of Masaya Yamaguchi’s 1989 Klein Bottle, as well as what I consider the most classic 2D work, Sword Art Online, and the previously popular film Ready Player One. In 1935, American science fiction writer Stanley Weinbaum published Pygmalion’s Spectacles. This story is considered the first science fiction work to explore a virtual reality system, describing a VR system that includes smell, touch, and holographic goggles. Up to this point, it seems we have only talked about VR as a science fiction element, and have not touched on the idea of setting-based mystery. In fact, science fiction elements can be considered a very common branch of setting-based mystery.
So what is setting-based mystery? Setting-based mystery refers to mystery works that introduce non-realistic elements such as science fiction, fantasy, or horror, and unfold reasoning under the rules of a special worldview. It comes from the British “Knox’s Ten Commandments” rejecting supernatural elements:
- There must be no supernatural power in the story.
- The story should not contain nonexistent poisons or crime tools so complicated that they require long explanations.
- There must be no Chinese character in the story. In practice, this was about banning characters with supernatural abilities.
Although these rules include some incorrect understandings, they were once regarded as golden rules during the golden age of classical detective fiction. The logic is simple: introducing these elements cannot convince the reader. For example, when answering how the victim died, if the author says “the culprit has supernatural powers and killed the victim remotely without leaving traces”, then normal readers will find it hard to be satisfied. Generally speaking, mystery novels default to the physical laws of the real world. So if the solution is a supernatural ability that has never been mentioned before, then there are actually infinite possible answers, and the process of reasoning becomes optional. Maybe aliens killed the person, maybe the victim was undead and was already dead, and so on. Of course, if the reader is told in advance that the culprit has supernatural powers, and that there is only one culprit under such rules, then introducing this suspenseful setting can make the novel more interesting. But these elements alone are not enough to create a good setting-based mystery. For a mystery novel, the author creates a puzzle, such as a murder case, and then provides a logically valid solution, or reasoning. If the supernatural element we discussed above has nothing to do with the puzzle and solution, then it cannot really be called setting-based mystery. For example, Detective Conan has the shrinking drug and Professor Agasa’s gadget tech series: skateboard, power-enhancing shoes, and suspenders. But these elements are not directly related to solving the mystery. When revealing the trick or identifying the culprit, their existence is basically not considered, so they usually are not regarded as special-setting mysteries. If Conan used high tech or the shrinking drug to commit a crime, then Detective Conan could be a setting-based mystery work.
At this point, we can introduce the full definition of setting-based mystery:
- It contains settings different from reality, such as physical laws, phenomena, supernatural powers, or high technology, but it must establish clear worldview rules in advance and follow the rules that arise from them. For example, the instruction manual in Death Note, or if superpowered people exist, constraints such as “only one person per region”.
- The puzzle must be based on the setting rules. In other words, the supernatural rules mentioned above cannot be unrelated to the puzzle.
In addition, even without any science fiction or fantasy elements, a mystery novel set on an isolated island, in a foreign country, or in the past, telling a puzzle and solution that can only exist under that background, can also be broadly called setting-based mystery. In fact, since the second half of the 2010s, along with the boom in special-setting mystery, there has also been a trend of highly praised serious mystery novels set in the past and centered on puzzles unique to that era, such as Seiji Furujo’s The Bottom of the War, Ibuki Amon’s Sword and Umbrella, Masaki Tsuji’s Just Murder, and Honobu Yonezawa’s The Black Prison Castle.
Japanese setting-based mystery originated from the new honkaku movement after Yukito Ayatsuji’s debut in 1987. In this new detective genre, which aimed to revive the fun of classical detection, one landmark work appeared: Masaya Yamaguchi’s The Death of the Living Dead (1989), which tells “a murder case in a world where the dead come back to life”. The pioneering part of The Death of the Living Dead is that it “created a completely special world in order to solve the mystery”. Next, Yasuhiko Nishizawa, who debuted in 1995, launched a series of science fiction mystery novels, including the landmark time-loop mystery The Man Who Died Seven Times, Personality Transfer Murder, which describes murders where personalities switch one after another, and the Sakugashi Tsugiko’s Telepathy Casebook series, which exposes crimes by telepaths. He promoted the idea that “even if you introduce a science fiction setting, as long as you clearly define the rules, you can write a mystery novel”.
In manga, intellectual battles, death games, and survival stories based on special rules, such as the previously mentioned Death Note and Future Diary, are very popular, and the form of “intellectual battle based on special rules” gradually became widespread. Looking back at this history, the strongest influences on modern fantasy mystery fiction are probably JoJo’s Bizarre Adventure and the works of Nobuyuki Fukumoto. Stand battles in JoJo, and the many special games in Fukumoto works such as Gambling Apocalypse Kaiji, form the foundation of the way fantasy mystery thinks. Also, when talking about the history of special-setting mystery, we cannot skip the popular game Ace Attorney, which began in 2001. The way Maya Fey uses supernatural powers to solve puzzles, and the unexpected events caused by supernatural powers, had a huge influence on young writers who debuted later.
Then in 2009, Yukito Ayatsuji’s Another came out, combining full suspense, the search for the real culprit, and plot twists based on horror-like rules. Later, in 2010, Honobu Yonezawa’s The Broken Keel appeared. It is a full-scale mystery set in a sword-and-magic fantasy world where the culprit needs to be guessed. The term “science fiction mystery” could no longer cover these works. The term “special-setting mystery”, used by Yonezawa in the afterword of The Broken Keel, later became widely circulated as a general name for mystery fiction that integrates science fiction, fantasy, horror, and other elements.
At the same time, the world of serious mystery fiction also saw the rise of multiple solutions, and the pursuit of “unexpected logic” gradually became mainstream. In the world of serious detective fiction, all unexpected culprits and tricks had long been exhausted, and surprising narration and plots using narrative techniques had also reached a bottleneck. Presenting readers with “unexpected logic” they absolutely could not imagine became the last frontier left for serious detective fiction. To present this “unexpected logic”, works began intentionally or unintentionally introducing non-realistic settings more and more often, such as special scenes built for logical battles in The Incite Mill and Marutamachi Louvre, as well as the “mirror that reveals the truth” introduced in Yuki Morikawa’s Snow White.
This multiple-solution craze, because it involved “multiple” solutions, inevitably developed in the direction of “winning by the number of logical steps”. It reached a peak in the mid-2010s with Reiichiro Fukami’s The Mysterious Arena and Masaki Inoue’s I Have Already Considered That Possibility, then stalled. Instead, works such as Tomoyuki Shirai’s Goodnight Human-Faced Sore and Yuto Ichikawa’s The Jellyfish Never Freezes appeared one after another. These works introduced unique settings and built puzzles according to those rules, constantly producing works that showed “unexpected logic”. In the past decade, Masahiro Imamura’s debut The Murders at Shijinso and Tomoyuki Shirai’s The Elephant’s Head are personally my favorite works in setting-based mystery. Besides them, Kie Hojo and Rin Hayasaka also have some good works.
The content below contains spoilers. Read at your own discretion.
Main text (with spoilers)
Back to the main topic. A Sweet Death for the Famous Detective uses VR virtual reality as its core setting, constructing a double closed-circle mansion across the “real world” and the “virtual world”, combining Werewolf and murder mystery game rules to unfold an intellectual battle between famous detectives and the culprit. The protagonist Toma Kamo, whose family has been kidnapped, is forced to participate in the beta test of the VR game Mystery Creator. The game stages are the real-world Megalodon Villa and the virtual Dollhouse Mansion. Players need to use VR equipment to solve cases in the virtual space, while players’ lives in the real world are directly tied to the game result. Among the eight participants, one plays the “culprit”, meaning the culprit in the virtual world, one is the “executor”, meaning the real culprit in the real world, and the rest are “detectives”. The culprit needs to commit crimes in the virtual space, and the detectives need to solve them within a time limit, otherwise the corresponding player will be executed in reality. Being killed in the virtual space does not mean dying in the real world. The physical rules of the virtual world are different from reality. Virtual cases and serial murders in reality happen simultaneously. While solving the VR locked rooms, the protagonist also has to expose the revenge plan of the Ryota Chikage siblings. They use the game rules to create chaos and try to reveal the curse of the Ryusen family to the public.
I will put the specific cases and puzzles in the appendix later, and those interested can read them. I think this part is decent in logic and innovation: worse than the best, Shirai and Imamura, but better than many weaker works. However, the biggest flaw of this work is still the setting itself. The core of setting-based mystery is to use limited special rules to compress special-rule logic into an extreme scene, thereby triggering trick possibilities that traditional honkaku cannot achieve. Masahiro Imamura’s The Murders at Shijinso uses only the setting of a “zombie siege” to construct a serial murder case that overturns tradition: the existence of zombies both creates the closed-circle mansion mode and becomes the key prop for “falsifying time of death”, such as when the culprit uses zombie bite marks to cover up the body’s real cause of death. When the reader thinks zombies are only atmosphere tools, they become the core of the trick. This creative thinking of “setting as trick” makes rules no longer decoration, but an indispensable load-bearing wall in the mystery maze.
By contrast, Hojo clearly chose a completely opposite path in A Sweet Death for the Famous Detective. This work tries to stuff VR games, real-world kidnapping, Werewolf role-playing, synchronized murders across virtual and real spaces, and other elements all into the same container. The result is that the core tricks are drowned in a huge and mixed setting.
In the novel, players need to use VR equipment to solve cases in the “virtual Dollhouse Mansion”, while life and death in the real world are tied to the game result. This setting itself already includes multiple variables such as “physical rules of the virtual space”, “time difference between reality and virtuality”, and “functional limits of VR equipment”. But the author further stacks on rules such as “Werewolf-style role assignment”, culprit, detective, executor, “administrator permission code tampering”, and “real-world kidnappers coercing players”, causing readers to spend a lot of effort clarifying what can and cannot be done. For example, in the case of “Yuki’s death”, the culprit uses VR camera focal length switching to hide the path of moving the body. The premise of this trick is that the reader must fully understand that “the virtual space of the Dollhouse Mansion has a scaling function”, but this setting is only briefly mentioned before the case occurs. The final solution feels more like “the author suddenly flipping over a hidden rule card”.
In excellent setting-based works, rules and tricks should be an integrated whole, like bone and flesh together. However, most cases in A Sweet Death show a split feeling of “setting is setting, trick is trick”. For example, the core method of “Kenzan’s death” is that “the culprit destroys the real-world VR equipment and causes the player to fall to death”. This solution essentially only needs the basic setting of “real and virtual linkage” to stand, but the author insists on introducing redundant settings such as “virtual gravity simulation system” and “anti-gravity rope misdirection”, which makes the trick seem forced. By contrast, in I Am a Yokai and You Are a Monster, Tomoyuki Shirai uses only one rule, “yokai must keep promises”, to construct an astonishing reversal where the culprit uses a language trap to deceive a yokai into suicide. Deep excavation of a simple rule is far better than flashy piling-up of complex settings.
Also, when rules become too complex, a work often turns into a cold formula manual, and the parts that show thoughts about human nature are easily ignored. The reason Masahiro Imamura’s Shijinso is moving is precisely that the zombie crisis magnifies human struggle, such as characters voluntarily being bitten to protect others. But in A Sweet Death, the revenge motive of the mastermind Ryota siblings appears pale and weak because of interference from VR rules, family curses, connections to previous works, and multiple layers of information. When readers are still struggling with “how does the virtual space synchronize real-world murders”, they already have no room to feel the characters’ despair and redemption.
The original intention of setting-based mystery was to break free from the constraints of real-world logic and open up new fields of tricks. But in recent years, some works have fallen into the misunderstanding of “setting for setting’s sake”, as if the complexity of rules is directly proportional to a work’s innovation. The danger of this tendency is that when writers become obsessed with building rule mazes, they may forget that there must be a shining jewel at the end of the maze: the logical core that makes everything suddenly clear. What readers expect is the moment of clarity when the truth is revealed: so it was that simple, but so unexpected. What they do not expect is still being confused after the answer is revealed: what does this puzzle mean, and what does it have to do with the setting?
A Sweet Death for the Famous Detective is undoubtedly an interesting work, but it also exposes the potential crisis of setting-based mystery: when rules become so complex that a manual is needed to understand them, a mystery novel mutates from “a game of intellect” into “a slave of setting”. By contrast, I prefer Tomoyuki Shirai’s infinitely looping Sisma, and the elevator and zombies in Masahiro Imamura’s lens. They use the simplest rules to tear open the deepest cracks of logic. Their success lies precisely in the fact that they hold “Occam’s razor” and decisively shave away every unnecessary rule setting. When setting-based mystery relearns how to do “subtraction”, maybe we can welcome the next golden age.
Appendix: Case and Puzzle Analysis of A Sweet Death for the Famous Detective
The novel designs five core cases. Each combines VR settings with physical tricks, presenting a complex structure of “virtual crime -> real-world linkage -> multiple reversals”.
1. Unknown’s death (virtual locked room: ice and air pressure)
- Method: In the virtual space, the player “Unknown” is found dead in a sealed room, with doors and windows locked from the inside. The culprit uses ice to block the ventilation opening and creates a pressure difference between indoors and outdoors through air conditioning, causing the door lock to close automatically after the ice melts and forming the illusion of a locked room.
- Key point: The VR environment simulates physical rules, but players need to realize that “a locked room in virtual space can be solved through real-world physical principles”.
2. Yuki’s death (double space and the Dollhouse Mansion)
- Method: In the virtual space, “Yuki” dies in the reduced model room of the Dollhouse Mansion. The culprit uses the blind spot created by VR perspective switching to move the body from normal space into the reduced model, creating an “impossible displacement”.
- Solution: Players discover that the Dollhouse Mansion model and the real space have matching proportions, and by adjusting the VR camera focal length, the path of moving the body can be hidden.
3. Kenzan’s death (rope and gravity misdirection)
- Method: In the virtual space, the body of player “Kenzan” is hanging from a high tower, and there are no climbing tools at the scene. The culprit uses the gravity simulation function of the VR suit to forge an “anti-gravity rope” in the virtual environment, misleading the detectives into thinking the culprit has flight ability.
- Reversal: In reality, the culprit damaged the VR equipment in the real world, causing Kenzan to lose weight support in the virtual space and fall to his death.
4. Munakata’s death (VR suit poisoning and time lag)
- Method: Player “Munakata” dies of poisoning in the virtual space, but the VR environment cannot directly poison someone. The culprit injected neurotoxin into Munakata’s VR suit in the real world in advance, using the delay between game time and real time to create the illusion of “virtual poisoning”.
- Key clue: The life monitoring system built into the VR suit shows that Munakata already had signs of poisoning before entering the game.
5. Fuwa’s death (virtual scene reconstruction and the executor’s identity)
- Method: The executor “Fuwa” is killed in the virtual space. The culprit tampers with game code and reconstructs the VR scene after the case occurs, covering up the traces of the crime. It is finally revealed that Fuwa is actually Ryota Chikage’s substitute, and the death is a “false solution” designed by Chikage to confuse the view.
- Core trick: The executor uses administrator permissions to switch identities between virtuality and reality, creating an alibi.
Reference
Niconico Encyclopedia
Some scattered thoughts on setting-based mystery
The world beyond settings