Just noticed this 3 page document was added to his website on April 7th.
Interesting information about hook types and sizes, but also a lot of fun to read the explanations for the names of the hooks.
http://www.hi-ho.ne.jp/amago/b-streams/flytying/pdf/Traditional_Kebari_Hook-E.pdf
The document is linked in the text from this web page.
http://www.hi-ho.ne.jp/amago/b-streams/flytying/kebari_study.html
テンカラ伝承毛鉤 (Tenkara denshō kebari) Tenkara Traditional Kebari ( or Lore or Folk Lore Kebari)
Also I just discovered a, new to me, Japanese phrase for Kebari Type. 毛鉤 種類 (Kebari shurui), which I guess could also translate as “kind of kebari”
It turns up a few different websites that I don’t find searching with 毛鉤 タイプ (Kebari taipu) Kebari type.