Rinse off the Red Beans the night before and soak overnight. Beans will have grown a lot overnight.
The next day, rinse off the beans and then fill a pot with water and beans, the water should completely cover the beans and have a little bit extra. Bring to a boil, and then lower the heat to a low simmer. Let simmer for roughly 60-120 minutes, until you can mush the bean with a gentle finger press.
Once done, drain the water, and then add the sugar. If you want fine Anko, use a food processor to get the paste, for rougher red bean paste, mush all the beans and the sugar together manually.