In a heat-resistant bowl, stir together the ingredients for gyuuhi (except for the milk and katakuriko) with a whisk. Slowly pour the milk into the bowl and mix well.

Cover the bowl loosely with a piece of plastic wrap and microwave at 700W for 1 minute. Remove from the microwave, stir with a spatula and microwave for another 30 seconds. Mix well.

Transfer to a tray lined with a little bit of katakuriko. Form sticks smaller than the diameter of your mold. Cover loosely with a plastic wrap.

Put finely chopped chocolate in a bowl, and warm up using a double boiler (about 60℃). Remove the melted chocolate from the double boiler (temperature of the chocolate should be about 45℃).

Sift the matcha with a tea strainer. Mix gently using a spatula.

Let cool, stirring constantly, with the bottom of the bowl exposed to cold water (about 15℃). The temperature of the chocolate should be about 25℃.

Warm up the chocolate again in a double boiler (about 35℃). (The temperature of the chocolate should be about 28 to 30℃). Pour the chocolate into the mold about halfway up. Gently tap the mold a few times.

Store the remaining chocolate in a warm place and set aside. The bottom of the bowl should be barely touching hot water underneath.

Cut the sticks from Step 3 with a pair of kitchen scissors (into appropriate thickness). Put the slices and the anko in the mold from Step 7. Gently tap the mold.

Fill the mold with the remaining chocolate, covering the gyuuhi. Gently tap again and store in cold place to harden the chocolate.

Chocolate shrinks slightly when hardened. Add more chocolate and let cool again as needed.

Scrape off excess chocolate from the mold with a spatula and refrigerate for 20 minutes. Take the chocolate out of the mold, and it's done.