If you are not so determined to be a Japanese teacher, you might as well learn another major across majors. Japanese is not a major, and language is just a tool, not a technology. If you have special skills and your original Japanese tools, you will have a wider road to job hunting in the future. Moreover, if the requirement for Japanese is only a tool for future work, then why do you want to go to graduate school? Nowadays, Japanese training classes in society can also help people meet the needs of work communication. If you have a unique interest in Japanese culture or language, if you have to go to colleges and universities for further study in order to satisfy your interest, that is another matter. I guess you're not, are you?
Therefore, I suggest an interdisciplinary exam. In addition, I would like to say that the progress made in studying Japanese in closed doors for three years in universities is not necessarily greater than the experience gained in a Japanese restaurant for one year.
Japanese graduates stay.