What do you mean by 'Tenkara Flies'?
If you mean flies with a reversed hackle such as this -


or this -


You may (or not) be surprised to know that neither of these flies are, strictly speaking, Tenkara flies.
The first is an Italian Alpine pattern tied in the 1960s,
and the second is one tied in 2006 by myself, and is based on an
article on this site by Preston Singletary -
http://www.flyanglersonline.com/flyt...080706fotw.php