In a microwavable bowl, mix glutinous rice flour, sugar, and water. Stir well until smooth.
Cover the bowl with plastic wrap, then microwave for 1 minute. Then unwrap and mix well using a spatula.
Cover the bowl again, and microwave for another minute. Then mix well. If the mochi mixture looks clearer and glistening, it's ready. If you still see some white spots, cover again and microwave for 30 more seconds until ready.
On a flat surface, spread potato starch, and plop the mochi on top. Coat the mochi with potato starch so it won't stick to your hands too much.
Flatten the mochi with your hands or a rolling pin until it's about 3-5mm thick, then cut it into 8-10 squares.
Take one mochi square in one hand, then bring the anko ball in the other hand, placing the tip of the strawberry in the middle of mochi.
Wrap the ball with mochi completely.