We recommend experimenting with different rigging styles until you find what works best for you. Here are a few things to consider when choosing line and tippet length.
*Tenkara rods typically work best with a line system that is approximately the same length of the rod, plus an additional 3-6 feet of tippet.
*Most anglers find that fishing line systems longer than 1.5 times the rod length begins to diminish their ability to keep the line off the water.
*Longer line systems increase the amount of hand lining that you have to do to land your fish.
*Tippet plays two important roles in the line system. First, it provides a stealthy, small diameter section of line to attach the fly to. Second, it is a "safety" section that is intended to snap off before the rod encounters physical forces that will damage it.
When we decided to sell our own rods, we experimented with many different line types. Eventually, we decided to try traditional PVC fly fishing lines, and quickly became impressed by how well they worked for Tenkara! We like these lines because they are durable as heck, they have almost no line memory, and they cast wonderfully. We also like the way you can feel the rod load with these lines versus traditional and level line. They still deliver the fly delicately (if not quite as delicately as a furled line) and they are still easy to keep off the water for a drag free drift. We have found them to be the best compromise between all of the line types, though fishing with them never feels like a compromise!
There are a number of different types of furled lines out there, typically made from natural fibers, though there are some folks making furled nylon lines as well. Furled lines have no line memory, so you can just unroll them and fish, no straightening needed. There are some downsides to furled lines. The primary downside is that unless they are treated with floatant, they will eventually get wet and water logged. Once that happens, it will be harder to keep the line off the water and you may get some drag. If you fish in freezing temps, the line will freeze.
A common choice because it is the lightest option available, level line offers its own set of advantages and disadvantages. On the plus side, it is the easiest to keep off the water, making it the best way to get that drag free drift. You can also customize it to whatever length you want, something you really can't do with traditional or furled lines. It is also comparatively inexpensive. That being said, it does have drawbacks. We believe it has the steepest learning curve of any of the three line choices, so we don't recommend it for beginners. It can also be difficult to cast in windy conditions. Level line has high "line memory" - so it tries to keep the shape it has been held in most recently. This means that you'll have to pull and straighten it out to remove kinks before fishing it.