First start by making the green layer. Combine all the ingredients in a microwave safe bowl. Mix until evenly combined and the rice flour lumps have been broken down. Place some cling film over the bowl and microwave on high for 2 mins. The mixture will become slightly bubbly. Take care, as it will be hot, and give it a stir. Place in the microwave for 1 more min. Give the mixture a stir again. Prepare a tray, we recommended an 8 in. by 8 in. size, and lightly dust the bottom with the potato starch powder. Carefully add the green layer to the tray and stretch it out into a thin layer to coat the bottom of the tray. Using a rolling pin if needed to help spread the mocha until an even thickness is achieved. Next, repeat step 1 for the remaining two layers and lay each additional layer on top of the previous one. First the white layer, then the pink layer. Dust the top of the mochi with some more potato starch powder. Allow to rest for 30 min. Then cut with a sharp knife into diamond shapes for a traditional feel, or into squares if desired. Enjoy with some hina arare rice crackers or some matcha tea for a sweet treat on Hina Matsuri.