The classical detective story has always been an unusually genre conscious branch of literature. Even the more straight faced versions are likely to be a little like parody in their readiness to make knowing references to the conventions of the genre. Japanese detective stories are if anything more self conscious than English and American ones. 安楽椅子探偵アーチー (anraku isu tantei āchī, Archie, The Armchair Detective, 2003) by MATSUO Yumi (松尾由美) makes reference already in its title to a convention of classic detective stories, the detective who solves puzzles by intellect alone, without visiting the crime scene, using only the evidence brought to him by others. The name Archie in the title will remind readers of the most famous armchair detective series, Rex Stout's Nero Wolfe books, in which Archie Goodwin is the sedentary Wolfe's more active assistant. The Archie in this book, however, is the armchair detective. More than that, he's an actual armchair, solving mysteries brought to him by his eleven year old owner, Mamoru (衛).
Mamoru bought the old armchair with the birthday money given him to buy a computer console, after noticing that the sound of breathing seemed to be coming from it. Having found that Archie is actually sentient, Mamoru mostly sits in a different chair facing him and discusses problems with him. He gives him the name Archie, since he cannot very well address him as "Chair", using the first two syllables of the English word "armchair" (you may be thinking that there's no "chi" in "chair": there is, if you write it in Japanese letters).
The mysteries that Archie solves generally belong to the genre known as 日常の謎, puzzles of everyday life, minor mysteries involving no major crime. There are four more or less independent stories, with some development carried over from one to the other. In the first, the bag that a fellow schoolboy had been making in crafts is vandalised, cut in half, so that the head of the octopus bodied alien he had painted on it is missing. In addition two teachers had been in the room that any vandal would have to pass through, and had seen nothing. Mamoru's friend, NOYAMA Fusa (野山芙紗), a detective story enthusiast, indentifies the case as a "locked room" mystery and a "headless corpse" problem. Detective story fans are often characters in Japanese detective stories, a consequence of the genre consciousness I mentioned earlier. The second story involves another impossible theft, the theft of a flower from the corsage of a young violinist. The third has Mamoru and Fusa investigating what looks like a secret message, chalk underlining of certain letters on a notice in the foreign graveyard in Yokohama, where the stories are set. The fourth breaks out of the pattern with a mystery rooted in Archie's past in wartime Shanghai. This adds elements of historical fiction and science fiction spy story, which is perhaps a bit much for a book that was already combining detective story and fantasy.