Prepare the Shiratama Dough: In a medium bowl, whisk together the shiratamako and granulated sugar. Gradually pour in the cold water, mixing well until the coarse granules dissolve and the mixture becomes smooth.
Prepare the Jyoshin Dough: In a separate bowl, add the jyoshinko. Carefully pour in the hot water and stir vigorously until a cohesive, warm dough forms.
Combine and Knead: Bring the shiratama dough and jyoshin dough together into one bowl. Knead them together thoroughly using your hands until smooth and uniform. The texture should feel soft and pliable, exactly like the consistency of an earlobe.
Color the Dough: Divide the unified dough into three equal portions. Knead the strawberry powder into the first portion until a uniform pink, and the matcha powder into the second portion until a uniform green. Leave the final portion plain white.
Shape: Roll each color portion into small, even balls about 2cm (1 inch) in diameter. You should get 11 balls of each color.
Boil: Bring a large pot of water to a rolling boil. Gently drop the rice balls into the water and cook for about 3 to 4 minutes.
Cool: Once the dango balls float to the surface, let them cook for an additional 60 seconds, then immediately transfer them with a slotted spoon into a bowl of ice-cold water to set the chewy texture.
Assemble: Thread one green ball, one white ball, and one pink ball onto each bamboo skewer in that exact order. Serve at room temperature.