*I was wrong about this. I simply was not looking for it before. I did find raw red beans, vacuum packed, as well as canned cooked - both sweetened and un-sweetened - red beans in our Japanese grocery store (only one left in DC area).
In any case, a quick internet search revealed more than a few entries on how to cook azuki properly. I read a few of them and amalgamated them into the recipe I used. I think the secret was that I was careful not to make it too sweet.
Azuki beans look like this (image below left), I think I had about 1 pound. I washed and soaked the beans in plenty of water overnight. I cooked the beans on high flame using the water they soaked in. When the water came to a boil, I turned the flame down to a vigorous simmer (if such a term exists--it is just a tad below "gentle boil") for 10 minutes. I drained and washed the beans in cold running water. I put the beans back in the pot and added fresh cold water (3 times the volume of the beans). After the water started boiling I turned it down to a vigorous simmer. Small white bubbles or scum soon covered the surface, I skimmed it off repeatedly. If the water level went down too far, I added more hot water. After 30-40 minutes, it looks like this (image below right). I tasted the beans, they were now soft. I set aside a portion of the simmering liquid and beans to use for other dishes, and continued making this dish. It appears important to add sugar in stages to keep the beans soft. So I added about 1/4 cup first. I cooked it for a while, tasted it (not sweet enough even for me) and add more sugar until I thought the sweetness was right (for me, that is. It must be a half of the recipe calls for). You could keep cooking to your desired consistency but I like it a bit soupy. I added a pinch (1/2 tsp) of salt at the end which supposedly enhances the sweetness.
My wife really liked this but said she would not consider it a dessert--Translation: "Do not attempt to serve this to me as a dessert. If you would like to serve it as a starch side with the meal--perfectly acceptable". In any case, I am planning to make some more savory dishes using azuki. No wine or sake will go well with this dish. "Bancha" 番茶 or "Hojicha" ほうじ茶, Japanese roasted tea will be the best bet as your choice of libation.