Motohiro Katou's C.M.B. is a companion to his Q.E.D. series starring Sou Touma's younger cousin, Sakaki Shinra, who's an orphan, of sorts, spending his childhood in England as a ward of three secretive curators of the British museum – gifting him three rings bearing the letters "C," "M," and "B." The letters could be the initials of the blessing Christus Mansionem Benedicat or of the names of Three Magi. History is not, exactly, clear on that matter. However, the rings provide Shinra with plenty of financial funds to do research and collect items for his museum. In addition to providing a certain level of authority to those who understand what it means to possess not one, but all three, rings.
A 14-year-old Shinra returned to Japan to start his museum, or wünderkammer, on the second-floor of a building, which is practically inaccessible except by climbing a tree branch leading to the balcony ("...entrance way got blocked off"). Just like his cousin, Shinra has a knack for cracking complicated, seemingly impossible problems and puzzles. So has to play detective, from time to time, but Shinra asks an admission fee to hear his solution. This is usually an item connected to the case or simply visiting his museum. It should be noted that the main difference between the two series is the subject matter. Q.E.D. has characters and plots couched in science, math and engineering, C.M.B. is more concerned with archaeology, anthropology and biology.
C.M.B. was originally serialized from 2005 to 2020 in Monthly Shonen Magazine and collected in 45 volumes, which appear to have started out following the same structure as Q.E.D. with two complete stories in each volume. From what I spotted, there are several volumes early on in the series comprising of one long story and more volumes apparently consisting of multiple, shorter stories – unless they're chapter titles to the same story. I'll find out soon enough.
"Mimicry" is the story opening the first C.M.B. volume and introduces the reader to the second lead character of the series, Nanase Tatsuki. A tomboy-ish student of Meiyuu Private High School, run by her illustrious grandfather, who's destined to play the Kana Mizuhara to Shinra's Sou Touma. It begins with a deadly incident in the biology class room of the school. Someone, presumably the biology teacher Tazaki, spontaneously combusted into flames and left behind a pile of ashes with two partially in tact arms sticking out. However, the arms prove the victim is not the missing biology teacher and now primary suspect. Tazaki happens to be the brother of one of her friends and classmate. What's more, Tatsuki spots a strange boy sitting on a tree branch opposite the biology class room with a pair of binoculars. So immediately begins to pursue him.
Tatsuki's chase ends when she finds the entrance to Shinra's museum to confront him, but Shinra claims he has nothing to do with the incident and invited her to return to his museum soon. Tatsuki continues to help her friend trying to figure out what happened to her brother in the hopes of proving his innocence, which eventually brings her right back to the museum. While he had nothing to the spontaneous combustion case, Shinra tells her Tazaki wanted to show him a rare butterfly from his collection. But never kept his appointment. Shinra offers to solve the case in exchange for the rare butterfly as an entrance fee to his wünderkammer (i.e. solution).
First of all, "Mimicry" is a setup story tasked with introducing the characters and setting up the premise of the series, before attention can be given to the individual plots. So the plot is not terribly complicated, however, I appreciated the solution to the spontaneous human combustion problem. I'm not sure SHC counts as an impossible crime without it being witnessed or happening in a locked room, but the method sure feels like a typical, shin honkaku-style impossible crime-trick – which deserved to be used in a story with more attention for the plot. Other than that, the introduction and portrayal of Shinra stands out. A genius when it comes to history and biology, but where the normal, everyday world is concerned, Shinra appears to be even more oblivious than his cousin on his first appearance. Shinra has no idea how vending machines work or that you can open a can of Coca Cola without a blowtorch. All in all, a good, fun introduction to the characters and series with a very decent plot to boot.
The next story, "Ghost in the Museum," is another fun, light story in which a nighttime security guard at the Museum of Natural Science has an encounter with the resident ghost. Tachibana Yoshiko hears disembodied sounds of banging, moaning and people crying as the lights begin to flicker. And that begins to take a toll on her. But she needs the job in order to take care of her newborn. Fortunately, Yoshiko knows Tatsuki from their aikido classes. Tatsuki knows a so-called "museum expert" who might be able to help. Shinra is only too pleased at the prospect of visiting a museum and curator is impressed with his knowledge, but astonished when Shinra shows him the three rings ("I never saw them directly, so I thought it was just a legend"). The situation takes a serious turn when that day's earning is stolen from the curator's locked drawer and Yoshiko's job security is in jeopardy.
From the ghostly occurrences in the basement room and their natural explanations to the stolen money, "Ghost in the Museum" reads like something straight out of The Three Investigators series (The Mystery of the Whispering Mummy, 1965) and other similar juvenile mystery series. The solution to the ghostly sounds is a little crude, or would have been in any other story, but here the setting complemented the trick. So a very slight, but fun enough, story with the ending setting up the next story.
The first story of the second C.M.B. volume, "Blue Building," continues setting everything up and introducing an important series regular, Inspector Takeshi Kujirazaki. Inspector Kujirazaki is naturally playing the Inspector Mizuhara, who has a walk-on cameo, to Shinra's Tou Souma.
Kujirazaki is investigating an assault at a four building apartment complex with their sides painted in the colors red, white and blue, but the case is getting nowhere until an anonymous letter arrives, "the culprit of the Blue Building case is the person who lives in the room on the bottom floor on the right side." Meanwhile, Shinra, who has never been to school, is doing an entrance exam and ends up becoming Tatsuki's classmate. Very much to her surprise. Shinra's exam went so well ("his social subjects scores, except for history, were terrible... apart from that, his scores were perfect") that he got tested again in an interview ("...maths, physics and chemistry knowledge is at the same level as a university student... history, geography and biology are even higher than that"). Other than that, there's not much that can be said about the story except that the solution to what the anonymous witness saw seems a better fit for Q.E.D. than C.M.B.
The last story from the second volume, "The Cursed Mask," is a good, old-fashioned and classically-styled locked room mystery and the best story from these first two volumes. Yamagishi Keiko, an ethnologist, turns to Shinra for help concerning a Noh mask with a deadly curse placed on it. The "mud stone" mask represents a woman who has been betrayed and Keiko has been searching for it, which recently resurfaced and man who bought it died of a blood cloth – infuriating his relatives who contacted the police ("...because they believed selling something like that was equal to murder"). Inspector Takeshi consulted Keiko and she turned to Shinra. And she knows someone else died because of that mask fifteen years ago. So the mask is back up for sale with two interested parties. Firstly, the previous seller and antique merchant, Iida Shigekazu. Secondly, the famous Noh dancer, Emoto Seimei. The negotiation takes place at the studio of the artist who sculpted the mask, Awa Saemon, who considers the mask "a failed piece of work" that needs to be destroyed ("my evil intention are attached to that mask"). Shinra, Tatsuki and Keiko travel to the studio to get a glimpse of the mask and to get information, but then the sculptor is found stabbed in his locked studio. Locked from the inside with the only key to the studio found on the victim and undisturbed snow on the outside window sill.
"The Cursed Mask" is an excellent shin honkaku locked room mystery in miniature reading like a modern take on Akimitsu Takagi's recently discussed Nomen satsujin jiken (The Noh Mask Murder, 1949). The locked room-trick is simple, but elegant, satisfying and brazenly clued. It's daringly alluded to before the murder is committed and discovered, which is the hallmark of every great detective story. Not merely a sound one. Even better is the backstory of the cursed mask and how it's very existence actually ended up destroying a man all those years before. A great story to close out this first excursion into the C.M.B. series and an early contender for that future post "The Hit List: Top 10 Favorite Cases from Motohiro Katou's C.M.B. vol. 1-25" (see my Q.E.D. version).
So the crossover from Q.E.D. vol. 41 and C.M.B. vol. 19 is getting closer and the current plan is to do Q.E.D. vol. 39-40 and C.M.B. vol. 3-4 next, before finally tackling that long anticipated crossover. Stay tuned!