"Looking for lodgings." I answered. "Trying to solve the problem as to whether it is possible to get comfortable rooms at a reasonable price."
"That's a strange thing," remarked my companion; "you are the second man to-day that has used that expression to me."
"And who was the first?" I asked.
"A fellow who is working at the chemical laboratory up at the hospital. He was bemoaning himself this morning because he could not get someone to go halves with him in some nice rooms which he had found, and which were too much for his purse."
"By Jove!" I cried, "if he really wants someone to share the rooms and the expense, I am the very man for him. I should prefer having a partner to being alone."
"A Study in Scarlet"
Reason: "Oh, that Lupin III vs Detective Conan crossover TV special a couple of years ago, oh, that was neat, but a bit too much on the safe side of things. So I shouldn't be too excited for the upcoming film sequel of Lupin III vs. Detective Conan."
Fanboyism: "To heck with reason! This is going to be absolutely awesome!!"
Morikawa Tomoki's Hitotsu Yane no Shita no Tanteitachi ("Detectives Beneath One Roof") has the additional English title of Two Detectives and One Watson, which I will be using. Over a century ago, a quest for reasonably priced lodgings that brought us the duo of Sherlock Holmes and John H. Watson. And reasonably priced lodgings are still very much wanted, so it shouldn't be that surprising that the same noble goal created a new detective - writer team. Or to be precise, detectives - writer team. Both of essayist Asama Osamu's new roommates happen to be private detectives, but very different kind of detectives. Asama himself refers to the two as the Ant and the Grasshopper (from the fable). Machii Yuito, always dressed in a neat suit, is a hardworking detective with an extensive circle of acquaintances. He works by checking the facts, making detailed observations and slowly building his way to the truth. Tenka Reisuke, mostly dressed in pajama, stays mostly at home, sleeping. He works by making brilliant deductions based on one or two observations. Asama's publisher agrees to his idea of writing a book based on one of the detectives. Which of them is going to appear in the book (and receive money)? The one who will solve the mysterious death of a man who starved to death in a storage room locked with a number lock, of which he knew the combination. Will the hardworking ant win, or the playful grasshopper?
The rival detective has always been one of my favorite tropes in detective fiction, though it is not a very widely-used one. Maybe it's because of the work it brings with it. Consider this, writing an intelligent detective isn't easy anyway, and with a rival, you need to write another one! The characters need to be close to each other in terms of deductive powers, or else the element of competition weakens. The trope is also often used in combination with fake/multiple solutions, the rival detective is then used to propose a fake solution, which the main detective corrects. One can for example think of Simon Brimmer in the excellent Ellery Queen TV series, or to the first appearance of Hattori Heiji in Detective Conan (vol. 10). The problem is that this is often invoked by giving the rival detective insufficient data, which lead to the fake solution. Of course, that can be seen as a character flaw (too hasty to be a good detective), but it leaves the question, what if the two detectives had access to the same information? In that respect, Anthony Berkeley's The Poisoned Chocolates Case is a better example of rival detectives. Even though the people there do use information only they can have, the starting point is the same and most of the information is indeed shared information. Or what about Van Madoy's Revoir series? In the private trials there, the ultimate goal for the defense and prosecutors isn't finding out the truth, but winning the case. There the detectives (defense and prosecutors) are tested by their gift of making up plausible and logical hypotheses. Here the rivalry isn't about the truth, but just about being convincing.
A more satisfying way to do the rival detective trope is by giving the rivals different methods of detecting. Tantei Gakuen Q has a great premise in that respect, as the children in Q Class all have different fields of expertise that influence their work method; Megu for example has a photographic memory, while Kazuma is more IT-oriented and Ryuu works with cold reasoning (it's not used up to the premise's full extent though). But this might even be harder to write, as a writer needs to come up with (at least) two characters who tackle on a case very differently, and yet as rivals they still need to be evenly skilled.
And in that respect, Two Detectives and One Watson is a very entertaining novel. The start of the novel shows a good example of the different thinking methods of the two detectives: whereas "Ant" Machii sums up a string of observations and list of facts that lead to the conclusion that narrator Asama has been to a certain restaurant before, "Grasshopper" Tenka arrives at the same conclusion with just one inference based on one single observation. Both methods are correct and lead to the same conclusion, but are very different. And as the story continues, we see more and more of the working methods of these two different detectives and it's a pleasure to see each of them tackling the case in a completely different way.
The structure of Two Detectives and One Watson is very similar to Morikawa Tomoki's Sanzunokawa Kotowari series: even though the plot deals with one large mystery (the man who starved to death), the story is structured in smaller mysteries that get solved as the story develops (whodunnit, howdunnit and whydunnit), like how the stories are structured in the drama Trick. Two Detectives and One Watson also has a great sense of speed, and never gets boring. Another thing Morikawa seems to have learned from his Sanzunokawa Kotowari series is changing the conditions every now and then to keep things exciting. Snow White for example started with an introduction of a magic mirror, with more and more functions of the mirror explored as the story continued. Two Detectives and One Watson also has some surprises to keep the reader, and the detectives on their toes. For example: Tenka is shown to be a genius detective, but his extremely short (yet corrrect) deductions offer too little material for a novel, so he actually has to do his best now to create material if he wants to get chosen for the book. The different methods of deduction and the ever-changing circumstances keep the reader's glued to its pages.
Finally, the mystery behind the man who starved to death in a room he could have left is surprisingly fun. At first, I thought that the case would only serve as a background setting for the competition between Machii and Tenka, but the solution turns out to be quite surprising and is sorta reminiscent of Higashino Keigo's The Saint's Salvation, in a twisted way. It works excellent in the context of this story and helps strengthen the Ant and the Grasshopper theme.
In conclusion, a very amusing novel. It's a light-hearted mystery that is simply fun to read, which is actually all the excuse you'll need for picking up the book. And Morikawa Tomoki's new Sanzunokawa Kotowari novel is out now too, so I'll have to pick that up one of these days.
Original Japanese title(s): 森川智喜 『一つ屋根の下の探偵たち』