Preheat oven to 190°C (375°F). Line 6 muffin cups with paper liners.
In a large bowl, add sugars to butter, and mix well using a hand mixer. Gradually add the egg, mixing well.
Add half of the cake flour, the matcha, and the baking powder, and mix with a rubber spatula. Then add half of the milk and yogurt, and mix. Repeat with the remaining flour, milk, and yogurt.
Mix in most of the orange peel and chocolate.
Divide the batter into 6 portions, and spoon in cups. Finally, top with remaining orange peel and chocolate.
Bake for 10 minutes, then lower the temperature to 180°C (350°F) and bake for another 10 to 15 minutes.