I've been loving for ten and two thousand years
I yearned for you even more after eight thousand years
"Genesis of Aquarion" (Akino)
I have a lot of books, but I am not a collector (I am a reader). I think the oldest book I have is De Geheimzinnige Japanees (review here), which is probably over a hundred years old (can't find the exact publishing year), but I only have that thing because I wanted to read the story, not to own an old book.
Ashibe Taku's Sanbyakunen no Nazobako ("A Three Hundred Year Old Box of Mysteries", 2005)?
The Morie Shunsaku series is Ashibe Taku's main series, featuring an attorney who also works as an amateur detective. Sometimes, his sleuthing is part of his main job, like in Saibanin Houtei, but he is just as likely to accidently stumble upon a mystery, like in The Castle of Grand Guignol. Ashibe basically uses the character for a variety of stories, meaning you never really know what you can expect from a Morie Shunsaku novel until you've started with it. Sanbyakunen no Nazobako lies somewhere in between the extremes: he was asked to solve the mysteries recorded in the book in his role as an amateur detective, but it's his obligation to his client (and curiosity) that has him go into the murder of Kumagawa.
Sanbyakunen no Nazobako is by any standards a very unique book. It is basically a story-within-a-story (or to be precise: six-stories-within-a-story), with the Morie Shunsaku narrative bookending the six stories recorded in the book. These six stories have no direct connection with each other: they are set in different times, different places and with different characters. We start off with a story about a traveler in the East in 1709 for example, but the next story is about the pirate ship the Sea Serpent in South-East Asia in 1721, while the one after that is in set in China in 1793. Each of these stories belong to a different genre. From a swashbuckling adventure to a Western to an record of an expedition in Africa: every story is unique and on the whole interesting enough to read on their own. Diversity is something that is defintely not lacking in Sanbyakunen no Nazobako.
The stories are obviously also mystery stories (or else I wouldn't be discussing it). The mysteries featured in the stories vary from impossible disappearances and murders to alibi tricks. What makes these narratives unique though is that the mysteries remain mostly unsolved within each seperate record. While some minor mysteries are solved, often the biggest question remains unanswered. Morie doesn't solve all of the stories until the very end of the book, in the final chapter. A problem here is that most of the mysteries aren't really that inspired. I'd say that this partly because of the unique set-up of this book. You have six stories that all feature a minimum of two mysteries (one to be solved within the narrative, one to be left unsolved until the end of the book), plus the murder in the bookend chapters. That's thirteen different mysteries and solutions. And that's not even the whole problem.
For the true unique feature is that Morie eventually explains each of the six unsolved mysteries at the end of the book and shows that each of the mysteries actually had a common factor, one that is even shared with his own murder case. So this book features thirteen problems that need to be solved, seven of which also need to have a common factor. The result however is that each of the problems is rather simple and not particularly exciting. Part of the reason why I'm not doing summaries on each of the short stories is in fact because the stories are so short, and the premises behind the problems so simple I don't think I could do a meaningful summary without spoiling something. Anyway, the solutions are usually so simple that not once do you really feel catharsis when a century old riddle is solved, and some are actually bad (the one in the story set in Beijing is ridiculous). None of the problems really have the time to build up tension because of the large number of stories. The book is certainly not short, so perhaps it would've been better if there had been less, but longer stories that could provide more complex mysteries. The fact each of the stories end with an unsolved mystery is also a bit... irritating. While you know the solution will come at the very end of the book, the fact each time you 'reset' everything (new setting/characters) for each story makes the wait for the conclusion feel even longer.
The 'connection' between the various mysteries is also suspect, at best. The common factor that Morie identifies, and which becomes a clue for his own case, feels very forced, as it almost requires Adam West Batman-logic to identify that factor in some of the stories. This hurts the overall book, because the premise is that Morie solves the six records, recognizes a pattern and applies that to his case: if the pattern is not obvious, the conclusion will fall flat.
While I don't think the experiment was a great succes, I do really like the idea behind Sanbyakunen no Nazobako. A lot of the books I've read by Ashibe Taku incorporate elements from the bibliomystery genre, and as this book is all about solving a crime through the reading of secondary texts, I think lovers of the bibliomystery genre can appreciate the effort. I also think the first story, A New Venetian Night's Entertainment, is really great as a bibliomystery. The 'murder mystery' is rather easy to solve, but the deeper reading of this text by Morie at the conclusion was fantastic. Very occasionally I see mystery stories do something similar, and when it's done well, it's really satisfying.
Sanbyakunen no Nazobako is a fantastic example of a great idea, but where the execution lacked. It definitely has some great moments as a bibliomystery, and it won't bore as each narrative gives you something new, but as a mystery novel it feels lacking, especially considering how absolutely great this book would've been if the concept had been executed perfectly. It might be going a bit too far to call it a missed opportunity, but there was definitely more that could've come out of this idea.
Original Japanese title(s): 芦辺拓 『三百年の謎匣』