To me tenkara fishing is when you are using a tenkara rod to cast a fly into whatever waters to whatever fish you choose to pursue. I think over time the technique will evolve and adapt better fit conditions found here in the US. To speculate more and get myself in more trouble yet, I think the name we use for tenkara here in the us may change to distinguish it from the way it is pratised elsewhere. Whatever definition you choose it is one heck of a lot of pure, unadulterated fun!