It would be a great way to introduce kids to fly fishing. I'd start them with the shortest rod, which is the one you'd probably want for small streams anyway. Casting a tenkara rod is pretty intuitive, and since it's a bit different than casting a regular fly rod, a complete novice may even "get it" quicker than someone who's been fly fishing for years. Not just kids, either. I had an email exchange just the other day with a guy who'd just taken up fly fishing and had gone to one of the full-day fly fishing classes. He came away a bit overwhelmed. There was too much to learn all at once. He was very happy when he learned about tenkara. It's just so much simpler.