Make a dough to mix shiratamako and tofu (or water) (refer to Recipe ID: 988641) It should be a bit softer than your earlobes).
Coat your hands with katakuriko, spread the dough thinly with your hands, and wrap the boiled anko (there's too much in the photo that it ripped).
Boil for 3 to 4 minutes, and serve with the cooking water. It's done. It is very soft, and different from normal mochi balls.
Story Behind this Recipe
This is a confectionary with shiratamako wrapped in anko. The authentic version is apparently wrapped with lard.
Use koshi-an or tsubu-an. It's difficult to wrap at Step 2, so do not put too much bean paste, or spread too thinly. If the dough does not stick to your hands, then you don't need to coat your hands with katakuriko.