Which masters degree would be the most beneficial?

I have a bachelor's in education and a full teaching license – of course I am looking to relocate to Japan, but before I do so I want to complete a masters degree.

I have several choices:

TESOL, Education, Linguistics, Japanese, or English.

Out of these, which is most likely to be the most beneficial to someone who legitimately enjoys teaching English, specifically in the context of Japan – I'm guessing TESOL?

What is anyone with a masters degree experiences in Japan? Thanks

by [deleted]