On the web, I found this basic formula for making the soup balls.
Ingredients
160-180 grams of the miso paste of your choice
5 grams of dashi powder (I recommend Ajinomoto brand Hondashi stock granules)
2 grams dried seaweed, chopped fine
Instructions
Combine the ingredients and roll the seasoned miso paste into 1 to 2 inch balls, depending on how salty your miso paste tastes. You can also get a uniform size and shape using a cookie scoop. Rehydrate them with 8 ounces of very hot, but not boiling, water. If you want to add additional flavor and make them look fancy you can cover the balls with toppings like sesame seeds or dried scallions. For the toppings, always use dry ingredients so they rehydrate when you add water. I’ve found it works well to first add half the water and stir to dissolve the miso paste and then add the rest of the hot water.
Beautiful photo recapitulating the misomaru box flower emblem. Clever! Each miso ball is a work of art in and of itself. The perfect roundness of the balls is impressive.