On a website that is a general handmade crafts diary I found this page about the making of 2 Tenkara poles.
The google translation is mostly unreadable to quite bizarre. However, the few images if clicked on will open larger in a new window and if clicked on again the images become even larger. Sometimes that helps to see more detail. Sometimes the image just becomes fuzzy from too much magnification. The gist of the post is that he made two bamboo tenkara poles. One softer and one stiffer. Maybe it will be a little fun to look at.
テンカラ竿の製作 Production/Fabrication of a Tenkara pole
http://kazika-koubou.at.webry.info/201106/article_5.html( note; I plan to post several links from the same parent web site about making various Tanago items. Bamboo poles, rod tubes and rod stands. )