Mii Studio (nintendo.com)

Editing a Mii in Mii Studio

Accessed at https://studio.mii.nintendo.com, Mii Studio is a web app for any Nintendo account user to edit their associated Miis.

Implementation

Through "reverse engineering" (lol) we have found out this information about Mii Studio:

Storage Format

Miis are stored in Mii Studio using the browser's local storage. They are encoded in base64.

...

Rendering

Mii Studio appears to render Mii data through layering. It uses WebGL to draw onto a canvas, and then does a series of draw calls with transformations.

Debugging Mii Studio's WebGL rendering with Safari