Here’s an inquiry that was posted on the Kumamoto-i mailing list:
“A friend of mine living in Kumamoto City is looking for a native speaker of English to tutor her children. If you are interested, please send me a message and I can put you in touch with her.” https://groups.yahoo.com/neo/groups/kumamoto-i/conversations/messages/12807
If you are interested, please contact the poster directly.