I love aromatic barley flour, which is similar to brown rice flour, and make these often. Barley flour mochi is a favorite with the young and old alike!
I once saw a recipe for barley flour mochi that used kudzu powder, but I substituted it for katakuriko, since it's readily available; It also makes the mochi translucent, chewy and delicious!
I recommend using koshi-an with barley flour. If not using any anko filling, increase the amount of sugar to about 100 g.
Enjoy Japanese food around the world.