Many tenkara anglers in Japan favor larger tenkara flies, even for trout in mountain streams. With faster flowing waters, larger flies give fish a good opportunity to see it and the potential high energy intake is too much for them to resist. Particularly effective for when the water is flowing fast, or for when the bugs are bigger, this size of tenkara fly should be in every angler fly box. Their forward-facing hackle also ensures a very lively fly underwater. This tenkara fly can be a very effective "secret weapon". Size 8. Three Flies.