Hi Mark,

thanks so much for your posting. The 'Nakahara' book I mentioned is the original source for the book "Japanese Joinery" which forms 1/2 of "The Complete Japanese Joinery".

While there a a few books in English that show a few rudimentary drawings - like Asby Brown's "The Genius of Japanese Carpentry" and the Engel book "The Measure and Construction of the Japanese House", there is nothing otherwise providing what you are looking for.
In Japanese the situation is somewhat better, and there are a few titles I am aware of....
If you want something along the lines of Hewitt, then the source would be the various documents done during reconstructions of Japanese National Historic Treasure Buildings - this possibly approaches 1000 monographs by now, and some of these are very detailed in terms of showing joinery, elevation and plan views, and 'kiku-zu' for roof curve layout. There are a few of these on file at the US library of Congress, but you need to know your Japanese terms to have a starting place for searching for them, since they are filed in romanized Japanese.
There is a 12 volume set on all aspects of layout that is available - the titles are listed on amazon.co.jp. and you need Japanese text method editor installed on your computer to use the search engine there. Unfortunately, amazon com Japan has few pictures of book titles to accompany their listings, so you really have to know your titles, be able to read chapter headings, etc, to make much use of it. Each book in that set I mentioned above would go for about $100 CDN, landed, if you are curious. There are also any number of layout books dealing with roof carpentry, and a couple of other titles dealing with overall house layout. One that comes to mind is "Zukai Mokkou Dentou Kouhou: Kihon to Jissai", which translates as "Illustrated guide to Traditional Woodframe Construction: Basics and Applications". That would cost you about $75 CDN landed, I imagine.
I guess the question is how far into the land of the Japanese language do you want to venture? Now, most of the books I can think of are mostly drawings, but the text has all sorts of valuable info. Sometimes they like to illustrate the wrong way to do something - and you would have no way of knowing that unless you could read it, so pictures alone can be misleading to an extent.
If I can help you in any way, please let me know.

Chris