Japan is really fond of these little red beans called Azuki (Adzuki). They are grown all around East-Asia and are used a lot in in all types of foods, like hot dishes, soups, porridge, confectionery, etc. Most popular however is the sweetened Azuki paste called Anko, which turns out to go really well with Matcha.
Check out this really nice matcha cake with anko filling for example. Would you be able to resist it? Right 😉
Alas, a freshly prepared cake like this will be out of reach for many of us westerners. Unless you feel like paying $$$ to fly it across oceans and continents in a couple of days. Not the best of ideas indeed.