TAKAGI Akamitsu (高木彬光) was one of the major Japanese mystery writers in the second half of the twentieth century, producing several books a year for decades. From the Japanese Wikipedia page, 1955 seems to have been a particularly productive year, with a total of twelve books published. At that rate, one should perhaps not have too high expectations of 人形はなぜ殺される (ningyou ha naze korosareru, Why Were the Dolls Killed? 1955); but it's a mystery with a high reputation, on the whole well deserved, with effective atmosphere and one especially pleasing trick.
The detective is KAMIZU Kyousuke (神津恭介), a professor of forensic medicine, amateur detective, and all round genius. His friend MATSUSHITA Kenzou (松賢研三), a detective story writer, functions as the book's Watson. We start with Matsushita visiting a café, whose curious and sinister ornaments derive from its owner's former trade as a professional stage magician. Kamizu is lucky that his cases so far have not involved magicians, the owner tells Matsushita. A magician, trained in the art of deception, would challenge him more than the killers he has dealt with so far. We soon have a chance to find out if he is right. At a meeting of amateur magicians, a guillotine trick is on the programme. The mannequin's head intended to be substituted for the head of the woman playing Marie Antoinette is stolen, so that the performance must be abandoned. Kamizu suspects there may be more to this mystery and advises Matsushita to look into it. Matsushita neglects the commission (he is playing all night Mah Jong). When he gets round to it, it is too late. The woman has been found guillotined. Where her head should be, the killer has left the stolen mannequin's head. This is the first in a series of murders in which the killing is announced in advance by the theft or destruction of a doll.
The initial theft is set up as an impossible (or at least very difficult) crime, but the investigation is not taken very seriously. In other respects though, the book is incredibly reminiscent of John Dickson Carr. Several characters feel like they have walked out of one of Carr's books and much of the stage scenery is clearly inspired by him (especially a lecture by Kamizu on black magic). Ellery Queen's challenge to the reader also makes its appearance. And YOKOMIZO Seishi contributes the serial targetting of three sisters from a once powerful landed Japanese family and an ominously threatening children's chant. Takagi's own interest in dubious finance is also already on show here. That ought to be all a bit much, but it all fits together very nicely.
I have a couple of reservations, neither of which made me like the book any less: the solution is probably a bit obvious and the book is longer than it should be. I say 'probably', because the way to the solution is made too easy, not just by Takagi, who plays perhaps too fair with the reader, but also by a careless description on the back cover of the paperback, which practically hangs a neon sign around the killer's neck. (The Japanese Wikipedia has a page on the book; and I'd avoid looking at that too until you've read the book, although it tries to avoid spoilers.) Around the middle of the book, Kamizu, who until then was commenting intelligently on the various puzzles, suddenly seems to forget even his own observations and become no better that than the average blundering policeman until the last couple of chapters.
My edition added two short stories, also featuring Kamizu, 蛇の環 ('The Ring of Snakes') and 罪なき罪人 ('Guiltless Sinner'); but I didn't have much enthusiasm for either of them.