I am a frugal tenkara angler, so is my 6 year old grandson, though he is not aware that he is!
You do not need to by a new Tenkara Fly Rod, just use the the fly rods you already have.
Do not install the reel to the fly rod, instead install a tapered leader or tapered furled leader to the the "Tip-Top" guide on the tip of the fly rod. If it is a 9 foot fly rod, use a 6 foot leader and a 3 foot tippet.
Casting upstream, and hold the rod angled so only a small segment of the tippet and fly are beneath the surface of the water.
As the fly travels down stream lift the tip of the fly rod so none of the leader of tippet is floating on the water surface.
As the fly passes your position, lower the tip of the fly rod.
When the leader is at it limits downstream, slowly raise the tip of the fly rod, to slowly retrieve the fly along the edge of the the stream bank you are on.
Do this three times, then move down stream about 10 meters and do it all over again.
~Parnelli
PS: Or you can sit on a dock on the edge of a pond or lake, casting to the sunfish, like my grandson and I do. Just lifting and lowering the tip of the rod to cause movement of the hackle in the soft hackle wet flies we are fishing with.