Onsen Manju

Divide the koshi-an into 10 equal portions, approximately 30 grams each, and roll them into smooth balls. Place the koshi-an balls on a plate and chill in the refrigerator.

In a large bowl, combine the brown sugar and water. Stir until the brown sugar is completely dissolved.

Add the soy sauce (koikuchi) to the brown sugar mixture and stir thoroughly.