In a heat-proof mixing bowl, combine the sugar, glutinous rice flour, rice flour, wheat starch, and coconut milk, then mix until there are no lumps. Note: we used three different types of flour, which can be challenging to find. You can use tapioca flour to replace glutinous rice flour and use cornstarch to replace wheat starch, but the texture will be different.
Cover the mixture with a microwave-safe lid, then microwave it on high heat three times for 1.5 minutes, 1 minute, and 30 seconds. Take it out in between and stir the mixture, then put it back in the microwave. The cooking time may vary depending on the power of your microwave, be sure to check the consistency until the mixture becomes a dough and there is no more running liquid. If you don't have a microwave, you can steam the mixture for 30 minutes.
Cover the dough and let it chill in the fridge until lukewarm. Add 1 tsp of matcha powder to the dough and knead until well combined. You can use any food coloring you want or leave it plain.
Divide the dough into 16 even pieces, and roll them into round, smooth balls. Each one should be 20 grams. Cover them so they don't dry out.