Requirements for Teaching English in Japan
Requirements for teaching English as a foreign language (TEFL) in Japan differ depending on where and what kind of job you are looking for. You will need a bachelor's degree to get an instructor visa from the Japanese government, though it is possible to find work without a degree if you are already in Japan.
If you want to teach English at a university or college in Japan, you will almost certainly need a Master's degree, preferably in TEFL, TESL, SLS, English, Linguistics, or some other related field. It is still possible to find lecturer positions with an MA in another subject if you have a TEFL, TESL, or RSA certificate. You should also have some experience teaching English in Japan.