Well, some universities allow you to "challenge" their proficiency language test, allowing you the credits w/o taking the class(es) necessary.
If you are talking about perhaps working for a city as a court translator, you do not need a degree, you just need to pass their test. If you pass it, you'll be certified to translate in court in Japanese.
American Translators Association (ATA) certifies translators and interpreters in many languages. The certification is accepted nationwide, check their web site. It is not a school, it ONLY tests applicants, if you pass the test, you will be certified.
Some employers require that bilinguals bring years of experience, including fluency in oral, written, and reading ability.
