Reviews
(4.22/5)This is a classic children’s detective book from the 1930s. 二十面相 is a gentleman thief and a master of disguise. He dislikes harming people, he politely sends letters advising when and where he will strike; and while stealing the item, before he makes his getaway, he takes a moment to stand talking to his victim explaining exactly how he pulled off the caper. Opposing him are the famous detective Akechi Kogorou and his precocious sidekick, the boy Kobayashi. The plot is fast-paced, and full of disguises, traps, gadgets, and chases. Is anyone who they say they are?
Reviews here and there from advanced readers estimate this as suitable for N3. But IMO whether this is actually true or not is going to depend on your goals, and whether you want to be reading intensively or extensively. If you thrive on challenge and you’re willing to put in lots of effort looking things up, then yes, you probably can do this at that level. However, if the goal is “comprehensible input” with minimal dictionary or grammar look ups, then this is a book for a considerably more experienced reader.
The basic sentence structure isn’t terribly challenging. This is not one of those books with long delicate sentences which require deep mastery of grammar to unwind. The writing here is straightforward. N1 grammar points appear, but you can look them up and keep going on, because the overall sentence structure as a whole will probably be in a comfortable N3-ish framework. It was much easier to understand than 銀河鉄道の夜. However, some characters have really thick/slurred character speech.
The challenge is vocabulary. To put the amount of vocabulary into context: by page 80 I had already looked up more new words than I did for all 160 pages of コンビニ人間, or all 360 pages of ペンギン・ハイウエイ. The settings and situations kept changing (because of exciting plot twists), so most of the words/expressions that were new to me were used only once. Furthermore, this is a detective story, so details matter. Often by a book’s halfway point I can use the dictionary much less, but the constant setting changes, continuing high frequency of new words, and the high comprehension necessary to follow a detective story made that difficult here until the very end. This was written in the 1930s, so the word choices are different from a modern book, including words for clothing, objects, and jobs which are no longer common today. Some words are spelled differently. There’s a lot of hiragana, and I had to look up many words which I would have easily figured out if the kanji had been used instead. I read a paper version so looking up all these words was especially painful. I’d suggest reading this book digitally instead.
If you like Nancy Drew or The Hardy Boys you'll like this book. The language is a bit old fashioned at times, but I think that provides even more learning potential as it's important to get exposure to that as well.
As a note, my version was a paperback copy containing footnotes explaining historical terms. I second the later review in that this will likely be easier read as an ebook if you're either unfamiliar with older vocabulary and/or you don't have access to an annotated copy.
A classic of mystery fiction
I just realized that my language learning rating/entertainment rating is the exact opposite of basilesauce, so I think I need to justify my rating a bit more.
In terms of language learning, the sentence structure is very straightforward, which means that it's easier to focus on the vocabulary. This book is aimed at a younger public, so you won't see any advanced kanji and many words are written completely in hiragana. Again, that means that you have to know (or learn) the vocabulary. Moreover, as mentioned in basilesauce's review, the book covers many different short scenes, each using their own set of words. All in all, that's a lot of words packed in one short book for you to learn.
In terms of entertainment, if you are familiar with this type of story (see cat's review), there's probably no development in there that will surprise you. And that's fine, since that means that you won't have to second guess your understanding of the content. Again, I feel that really helps focus on the learning. Anyway, it's a classic of the genre in Japan and the titular character (as well as other characters from the series) are often referenced in pop culture, so it's not a bad idea to read it.