TubeNet

Not schools, but I used to keep in contact with tuba teachers in the area around Tokyo.

I lived in Okinawa for a while and remember there being no tuba teachers on the island. There was one music college/university on the island but I don't remember there being an actual tuba teacher. The island is really small and is kind of... how do I say this... doing a lot of catching up in technological and social sense. But then again, things could've changed since I left.

Try asking around at the local jr. high or high schools band directors, they might be able to guide in the right direction.

Isn't Roger Bobo in Tokyo?

Yes. Contact him.

http://www.rogerbobo.com/

I implied that I lost contact with the tuba teachers I knew in Tokyo (two because they died!)