Prepare your oak leaf by rinsing and patting dry with a paper towel or kitchen linen.
Next make your mochi dough by whisking joshinko, sugar and starch. Add your filtered water and using a spatula, mix to create a smooth batter.
Cover the bowl with plastic wrap and microwave for 30 seconds. Remove from microwave and stir. Repeat 2 more times until a dough forms.
Sprinkle joshinko onto a cutting board or working surface and gently knead the dough. You can also pound it until it becomes smooth and shiny, and easier to work with.
Divide dough into 4 parts and roll into large circles. Take 1-2 tbsp of red bean paste and add it to the center of the circle then seal the edges tightly. Shape into more of a perfect circle once tightly sealed.
Wrap with an oak leaf, vein side out and enjoy! They are best enjoyed the same day.