In a medium bowl, whisk the yogurt, honey, vanilla and matcha powder together; gently whisk in the coconut milk, then chia seeds. Cover and refrigerate for at least 4 hours or overnight.
In a regular, or small personal size blender, blend mangos until smooth. Transfer to a container, and leave in the refrigerator until ready to serve. (This step can also be done the day you plan to eat it).
When ready to serve, pour into 4 serving bowls or glasses, and evenly distribute the mango puree over each serving. Sprinkle over some unsweetened coconut flakes if desired.