I found a Japanese channel where someone is using moe characters with TTS voices to teach maths. They've started translating their own videos into English.
Differentiation is an Infinite Matrix: https://youtu.be/6ibRcJi1bgA?si=xOCsZy6sLdSgLlD4
Binary Numbers? No, They're Not...: https://www.youtube.com/watch?v=dNySdycX-MU
Dual Spaces: The 'Underworlds' Of Mathematics: https://www.youtube.com/watch?v=rpBAUxXI1kY