Peel 2 pieces of ginger, cut them into thin strips, and soak them in water. Drain the water well.
In a pot, add the seasonings (300 ml of water, 4 tablespoons of soy sauce, 2 tablespoons each of cooking sake and mirin, and 1 tablespoon of sugar). Heat the mixture and, once it comes to a boil, lower the heat and add the ginger from step 1. Simmer for about 20 minutes until most of the liquid has evaporated.
When the liquid has almost evaporated, add 1 pack (4 grams) of katsuobushi (dried bonito flakes) and mix well. Add an appropriate amount of white sesame seeds, mix thoroughly, and the dish is complete!
