Firstly, I personally hate this rule. Second, I firmly know that tiers fantasy is the worst enemy of effective flies, because generates too many new patterns to be tested properly. I like to develop new flies, but I like to develop effective flies even more. I hardly test my patterns myself. I give away dozens flies to my friends and fishing companions and gratefully wait to receive their feedback. In this fashion I manage to achieve my main target – to work out a “trusted fly” patterns.
As for kebari flies, I am far from both the “one fly philosophy” and the “match the hatch paradigm”. By following the simple rule of "match the waters" when referring to the fish species, flow, depth, river bottom material, season, vegetation in and around the water, has given me many happy hours of fishing and a lot of fun merely catching fine fish. Some of this flies are available at tenkara gear store kebari page.
Oleg Stryapunin aka tenkara.cz