A lot of schools want native English speakers, but it's not an absolute requirement to be hired in Japan. I know several teachers from foreign countries who teach here. You do however to need to me native level, so fluent English.
Here's what the program says about it: https://www.internationalteflacademy.com/teach-english-in-j… While most job postings do require a degree, I know people without one who have found employment. It's much easier to do that here on the ground than from abroad though. Teachers will need their school/ company to sponsor their working visa. If said school/ company is hiring online or from abroad...
A lot of schools want native English speakers, but it's not an absolute requirement to be hired in Japan. I know several teachers from foreign countries who teach here. You do however to need to me native level, so fluent English.