Sift the matcha powder into a small bowl to break up any clumps and set it aside.
Add the coconut milk and coconut yogurt to the blender first, then add the sifted matcha.
Blend on low for 10 seconds until the matcha fully dissolves and the mixture turns pale green with no dry flecks.
Add the frozen mango, sliced banana, chia seeds, and honey (if using) to the blender.
Blend on high for 45 to 60 seconds until smooth and thick, scraping down the sides once if the mango sticks to the wall.
Check the consistency. Blend in a few ice cubes at a time for a colder, thicker smoothie, or a splash more coconut milk if it's too thick to pour.
Taste and add more honey if the mango was more tart than sweet.
Pour into two glasses. Top with a few mango chunks, a pinch of chia seeds, and a light dusting of matcha if you like.
Serve right away. The smoothie separates and the matcha settles within an hour.