Genmai is roasted brown rice, it's blend with green tea to make Genmaicha. Genmai Matcha is Genmaicha with added Matcha powder. Genmai gives the roasted nutty flavour of the tea, the added Matcha powder enhance the overall flavour with extra umami and astringency.
Normally Genmai-Matcha is a blend of roasted brown rice, low grade green tea (Bancha) and low grade Matcha. Our Genmai-Matcha use better tea leaves (Sencha) and higher grade Matcha.
On the other hand, the teabag material and shape is very important. The nylon material, pyramid shaped teabag allow much greater water flow similar to brewing tea leaves with teapot. Compare to normal square teabag, the much greater space in pyramid teabag allow us to use tea leaves instead of tea dust.