Prepare a 9x9-inch baking dish by sprinkling kinako over the surface in a thin but even layer. Set aside.
In a pot, add the warabi mochiko, sugar, and 1 ¾ cups of water. Use a whisk to stir thoroughly.
Put the pot over medium heat and stir occasionally for several minutes until it begins to boil.
Turn the heat to low and use a spatula to strongly beat for around 10 minutes. You want the mixture to get thick and translucent. It should be the same consistency throughout and a whiteish-clear color.
Take the pot off of the stovetop and pour it over the previously prepared baking sheet. Use a spatula to spread it evenly.
Use some more kinako to cover the top by sprinkling it through a small sieve.
Leave the mochi to cool in the fridge for half an hour, but no longer.
After the mochi has fully cooled, remove it from the fridge and cut into cubes.
In a large bowl, add ¼ cup of kinako and put a few cubes of mochi in it at a time to toss with the kinako in order to cover all sides. Repeat with all pieces and add more kinoko as needed.
To make the syrup, add the brown sugar and ½ cup water into a small pan or pot.
Place the pan over medium-high heat and stir gently. Bring to a boil, then turn the heat down to low.
Allow to simmer for 15 or so minutes, stirring occasionally. The sugar should have completely dissolved and also become thicker like syrup.
Once the syrup is thick, remove from heat and allow to cool. Make sure the syrup has reached at least room temperature before pairing with the warabi mochi.
Place the warabi mochi on a place. Before serving, pour the kuromitsu over and enjoy!