Preheat oven to 300 degrees F (150 degrees C).
In a large bowl, sift the Almond Meal (80 gram) and Powdered Confectioners Sugar (80 gram). Mix it well with a spatula.
Beat the whites of the Egg (70 gram) on low speed using an electric mixer until it is white and frothy. Gradually add the Caster Sugar (90 gram) 1/4 at a time.
When the first addition of sugar has completely dissolved, increase the mixer speed to medium and repeat step 2 until all the sugar has been incorporated. Continue to beat the egg whites and sugar until stiff peaks form.
Add the meringue to the dry mixture, followed by a few drops of Black Food Coloring (3 drop) for the grey coloring.
Using a spatula, start the macaronage process until you get a molten-like mixture and drips down like a ribbon when lifted.
Transfer the batter into two piping bags - a large one fitted with a round tip and a small one with a small piping tip.
On parchment paper or a baking mat placed over a baking tray, pipe out oval-shaped macarons from the large piping bag. After piping, knock the bottom of the tray against a flat surface to get rid of air bubbles.
From the small piping bag, pipe out two triangles for Totoro's ears.
Let the shells dry for approximately 30 minutes in an air-conditioned room. You should be able to touch it gently with the tip of your finger without it sticking. Bake for approximately 15 to 17 minutes.
While the shells cool down, prepare the black chocolate filling. Bring Heavy Cream (80 milliliter) to a simmer. Pour heavy cream over Dark Chocolate Chips (80 gram) and let it sit for 1 minute. Stir with a whisk until all the chocolate has melted, then let it cool.
For the black sesame filling, stir Water (2 tablespoon) and Black Sesame Paste (2 1/2 teaspoon) together. Pour it over the White Chocolate Chips (50 gram) and continue to melt the mixture over a water bath. Let it cool.
Transfer the fillings to separate piping bags and pipe about 1/4 of the flat side of a macaron shell. Top with another shell.
Decorate eyes, belly and markings with Royal Icing (to taste). Serve and enjoy!