It's too sweet if made with store-bought condensed milk and adzuki, so I came up with my own recipe.

I used homemade anko, which doesn't contain much sugar. If you use store-bought quality, reduce the amount of sugar. It has to be sweet to a certain extent or it won't taste very good, so add more if necessary. If you use 2 tablespoons of skimmed milk, you'll have an even milkier finish. Recipe by Akahoppe