Condition: very good. Edo (Tokyo), Suharaya Mohei 1795 (Kansei 7). 29x20cm publisher's wrapper with printed title label (covers a little nibbled). 22 double leaves plus pastedowns accordian folding, all but two leaves are large working drawings that in several cases extend over a few leaves and can be opened out to long drawings (longer than I can illustrate here). A bit of worming in the top margin of some leaves, nothing serious. The title translates as 'Top secret hexagonal template'. According to the English abstract of a paper by Humoto Kazuyoshi (The Design of Eaves Camber in the Japanese Traditional Architecture, 2002) "Design of eaves has been considered to be very important to construct the exterior shape of the traditional Japanese architecture. While many Japanese architectural books were written in the Edo and Meiji eras, the book about eaves camber design was not found until 'Banshouke Kayaoisori Mitugousinri,' which was written by Tousai Kiko in 1864." Unfortunately the paper is in Korean and I can only find it as a photographic image. Our title does appear in the references but as a 1976 publication by a different author. Worldcat finds only a manuscript copy in the Peabody Essex Museum.