The common background to most of the points below, is that Japanese writers have something of a struggle, if they want to get by as writers, enjoying a potentially large market in their own country, but (for most of them) only there. Despite its difficult writing system, Japan clearly has a high rate of literacy. Whether the 99% literacy you'll often see in reference works is based on anything solid is slightly questionable, as the last time Japan seriously investigated its own literacy seems to have been in 1948 (and it wasn't 99% then); but you can find small international surveys in which Japan really does score better than other developed countries.
- The importance of prizes. There are a lot of prizes in the Japanese book world. My impression is that there are more of them than in England or America. Very often when you read a writer's first novel, you find it was submitted for a prize for first novelists, whether it won or not. The Edogawa Rampo Award is the most important of these in the context of detective stories. Ellery Queen is the only writer who comes to mind, who started his career like that in the west; but doubtless there are others. Still the biographies of Japanese writers almost always mention that the first work was submitted for a prize; and I can remember at least one fictional first author depicted working towards a contest deadline. Since a writer is likely to want to go full time from the first publication (see point 3 below), the prize for a first publication is probably important both for publicity and for its actual value.
- Serial publishing. Many of the classics of Japanese crime literature (and other genres) were serialised in newspapers or magazines before being published in book form. You still sometimes see this mentioned even with recent books. The heyday of serial publication in England was the Victorian age; and almost all the classics of that time were first published in magazines like Dickens' Household Words. In the twentieth century, occasionally a magazine or a weekly paper would serialise a book; but it was always (in my lifetime, at least) an exception. The only crime fiction example I can think of in England is Kingsley Amis's The Crime of the Century, written for The Sunday Times in 1975 (and completely worthless). The background for the importance of serials in Japan is perhaps that the Japanese are huge newspaper and magazine readers. Getting a serial is another mark of success within detective stories, when a fictional writer is being described.
- Prolific authors. There are a few writers in English famous for the conveyor belt like book production that they kept up, John Creasey and Erle Stanley Gardner, for instance. AKAGAWA Jirou (赤川 次郎) and NISHIMURA Kyoutarou (西村 京太郎) have similar productivity in Japan. Each has written more than five hundred books. But even if you forget these famously prolific writers, a large number of books seems to be almost the rule for Japanese writers. A typical publication speed in England or America might be one book a year or slightly less, with some writers managing two and only the most prolific getting near three for any length of time. Looking at a writer's first twenty years of publication, if I've counted right, SHIMADA Souji has over sixty books, ARISUGAWA Arisu has 38 (excluding a large number of edited anthologies and books with co-authors). My impression is that successful writers nearer the one a year rate are fairly rare. One reason might be that Japanese employers look for more devotion from their employees and side jobs like writing are seen as an indication that their heart is somewhere else. The consequence is that the discovery that an employee is also publishing novels can lead to dismissal (this too crops up as a consideration with one of the fictional authors in a book I read). Most professional writers in England probably make their main living with a job of some kind and write what they can in their spare time until they become sufficiently established to risk writing full time.
- Translation. You can probably see that the label "books with an English translation" in the sidebar doesn't have many entries. It's incredibly rare for Japanese books to get a translation; and in fiction, "his books had been translated into English" is used to indicate a hugely successful writer. This is perhaps the reason why the covers of many books feature an English translation, or an alternative English title, even though the book has never been translated. The English often sounds slightly off. Sougen suiri bunko, which specialises in translations of English mysteries, generally manages competent English titles (and adds them to almost all their books).
- Bookshops. I've mentioned this before, but finding a book in a Japanese bookshop can be difficult. Most are arranged not by genre, even in the broadest sense, but by publisher. This means that if you're looking for a particular book, you need to know the publisher in advance. The reason for this, I imagine, is the difficulty of Japanese names. Written with Chinese characters (kanji), their meaning is not always immediately evident even for Japanese readers. So the spine of a typical paperback will look something like the photo below. At the top is the name of the author in kanji (NORIZUKI Rintarou). Below that is the first letter of the family name in hiragana (the Japanese syllabic alphabet), の ("no"). Below that is a number, 75, showing the place that the book takes in this publisher's list of its books by writers whose names start with "No-". So when putting books on shelves the bookshop staff only have to read the letter-number combination to find the right place.
(Sorry for the formatting of this post, by the way. I can't quite get Blogger's software to put that photo where I want it.)