Byron,

The biggest difference is that the tenkara line is so much lighter than any fly line. You can keep a lot more of it off the water's surface, so don't have to fish almost under your rod tip. You can fish on the other side of a current seam and never have to mend, because the line isn't on the water.

Another difference is that the 10' rod is really on the short side for tenkara. Casting distance is significantly less than rod length plus line length plus tippet length, because the rod tip is kept high. The longer the rod, the longer the line it can handle easily, so the further away you can fish and the fewer fish get spooked.

It is hard for people to imagine how light the line is until they try it. Most tenkara rods can easily cast an unweighted wet fly with nothing more than say 13' of 0X fluorocarbon tied to the rod tip, followed by 3-4' of 5X tippet - and still protect the 5X well enough to land 20" trout.