Cha Soba with Tsuyu Dipping Sauce

To prepare the dashi, place Kombu in a pot with Water for dashi and bring to a gentle simmer over medium heat. Just before boiling, remove the Kombu.

Add Katsuobushi to the simmering dashi, turn off the heat, and let it steep for 5 minutes. Strain the dashi through a fine-mesh sieve, discarding the Katsuobushi.

For the tsuyu dipping sauce, combine the prepared dashi with Koikuchi soy sauce, Mirin, and Granulated sugar in a small saucepan. Bring to a gentle simmer over medium heat, stirring until the Granulated sugar dissolves. Remove from heat and allow the tsuyu to cool completely, then chill in the refrigerator.