A very short book – best read at speed, without stopping. The momentum will carry you through the explanation at the end, which goes on for several chapters longer than it really should. Most of the book is an energetic ride that revels in baffling details and the tropes of classic Golden Age detective fiction. Until the denouement it steadily increases the pace and unveils a twist that will shock you if you haven’t been paying attention. The many historical details that form part of the milieu also make this an absorbing way to learn about a totally different setting compared to that of both Western fiction from the period, and to modern life.

An unusual – and to me, charming – point of this book is its framing device. The story is narrated by a detective-story writer, who is presenting a “true crime” to the reader based on primary sources. His visits to the scene of the crime, the Ichiyanagi Residence, bookend the novel. The charm comes from the narrator’s obvious enthusiasm for the story and for detective fiction in general, and his tendency to break the (internal) fourth wall to reveal information to the reader. It’s a technique I would typically associate with children’s fiction. In this case it gives the sense of the story being told to you by an engaging and very enthusiastic friend.
I’d like to take a moment here to praise the translation. Louise Heal Kawai apparently took great care over the tone of this aspect of the book and it really shows, it’s so fun to read. There was never any jarring point where I was forcibly reminded I was reading a translation, and though there is a huge amount of context and information to ensure the reader understands, it is all delivered seamlessly and effectively.
To return to the “framing narrator”, the use of this device does have its flaws. While endearing, the narrator’s tendency to refer to titles in the Western detective fiction tradition can become distracting, such as when the narrator either delegates the description of the detective’s personality, or explains the concept of an amateur detective, by referencing A.A. Milne’s The Red House Mystery. That said, I did recently learn about honkadori, where traditional poetry would reference other poetry that had entered the “canon”, and I wonder if that explains this odd aspect of the book.
The framing device doesn’t really stand up to scrutiny; the story is apparently based on notes from the town doctor, but instead the perspective hops around, often following Ginzo, the bride’s uncle – until the end, when the narration switches to first person from the doctor (who has barely appeared in the story) “directly from the notes”, at the point where things would become the most emotionally affecting for Ginzo. For most of the book Ginzo is the emotional centre of the story, and then, disappointingly, he gets forgotten about come the ending.

The book does actually spend more time on character than much classic detective fiction – unfortunately, this comes in a great lump during the denouement and is one of the causes of the sudden drop in pace. Aside from that, the story simply moves too fast to linger on the characters. For the most part, characters are simply a role, a name, and maybe a character trait if they’re lucky. The detective, Kosuke Kindaichi, gets a little more attention. This is his first outing, and we get a snippet of somewhat-unconvincing backstory, but certainly his appearance and mannerisms are distinctive, and his personality is quite appealing – though my memory of his other cases suggests that his excitement at being presented with an intricate crime diminishes, where his sense of the tragedies he is witness to increases. In this book he is quite a playful figure, teasing the police inspector whenever he reacts with shock, and deliberately concealing information so he can set up a dramatic reveal. The only other characters to really emerge naturally during the course of the story are the grieving Ginzo and the “slow” (as the book refers to her…) Suzuko.

The puzzle is – as the book itself points out – patterned after the most complex ones of the Western detective story tradition. With its locked room and missing footprints, the obvious inspiration is John Dickson Carr. The solution to this worked well – it’s scrupulously fairly clued, so that I had an inkling of the workings of it just as the denouement began. The explanation for the locked room is demonstrated before our eyes in a nicely visual way. But there’s a lot more to explain than that, or at least Yokomizo believes there is. The explanation of these other clues and red herrings is another part of that denouement slowdown I mentioned. Not only must Kindaichi explain what happened, it seems he also must explain how the culprit came to think up their cunning plan. I’d like to point back to the analysis of Carr’s work from the previous review. Carr’s best denouements feel punchy because all the extraneous explanations have been cleared up first, leaving only the central questions of who and how until the end. I wonder if some of the explanations could have been split apart – and yet, I can’t think of a way to do this here; each aspect of the plot is so intricately linked with the next. That’s the strength of the plot, but also the weakness of it.

Since I first read this book, I’ve seen and heard a lot more critical takes on it, and also read way more mystery fiction. I was worried this book I’d had so much fun with the first time would disappoint me on the re-read.
But I had nothing to worry about: The Honjin Murders had me racing along on its joyful thrill-ride all over again even though I knew what happened next.
I think the seasoned reader of classic detective fiction will get the most from this book – they’ll actually be able to understand all the references. But the references aren’t what made it so enjoyable, for me, so I think anyone who appreciates a complex, fast-paced mystery will enjoy this.

Other opinions:

Ah Sweet Mystery
Beneath the Stains of Time
The Case Files of Ho-Ling
Countdown John’s Christie Journal
crossexaminingcrime
In Search of the Classic Mystery
The Invisible Event
James Scott Byrnside
Mrs. K. Investigates
Mysteries Ahoy!
Solving the Mystery of Murder

Other notes:

Ho-Ling discusses an intriguing “modernized” film version of the book that I would very much like to see here.
This episode of Jim Noy’s podcast In GAD We Trust featuring the translator Louise Heal Kawai was very enlightening.
Flex and Herds tackled The Honjin Murders on their radio show Death of the Reader : Part 1, Part 2, Part 3. Full spoilers as always for that show!