Are interpreters/translators needed in japan? What do these fields essentially contain?

I am trying to discover my plans for the future and prepare for the preparation. I am curious enough to read the thoughts of people who might have valuable (maybe experienced?) insight on my questions. Seeing from the nature of my career choice, I am considering working in Japan. For an interpreter between English and Japanese, what is the outlook of this career path in Japan? Also, what are the common practices in this field? Do interpreters travel much? How many years of experience/progression in average does it take before financial stability is high enough to support a family? My questions might be vague, but I'm simply looking for what people might have noticed/experienced. Things might be different for everyone, I understand this. Approximates are all that I desire.