Remove the outer shell and the inner skin from the chestnuts, and let sit for around half a day in water to remove scum.
Wash the rice and mochi rice, and soak in water for 30 minutes.
Put the drained rice from step 2, salt and sake in the rice cooker, and pour water up to the 2.5 cup mark. This will give a firm texture. If you prefer it softer, add more water.
Add the chestnuts from Step 1 and switch the cooker on.
When it's done, give it a gently stir.
Story Behind this Recipe
This is my family's standard chestnut rice.
If you only add a small amount of mochi rice, it will be fine with the amount of water used for normal rice. However, if you would like it softer, let it soak for longer, or add water up to just before the 3 cup line in your cooker.