A spouse visa gives you the right to work at practically any job, yes, that's true. However, it is not anything more than that. To actually land the job, you have to show certain qualifications, and for non-teaching jobs that (as I wrote) usually means you have to have good Japanese skills and the necessary background.
Want to see what you're going to need? Go to
www.daijob.com/en and see what the language requirements are for jobs in your field. Please also take the link to Terrie Lloyd's huge warehouse of articles on work in Japan and read them.
Non-native people teach English. Getting such work is harder than for native English speakers, yes, but it can be done. Your misspelling of "tongue" (tang) and "studying" (studding) suggest that you need to work on your English skills, but I'm not trying to be a spelling policeman here. Maybe those were just typos.
There are many skills, besides teaching English that a gaijin can offer to Japanese companies, different ways of thinking, different approach to problem solving.
But many Japanese companies don't want different ways of thinking or different approaches to problem solving. They hire Japanese out of college regardless of grades, thinking mostly of the name of the university and the recommendations they get from the J professors who have ties with the companies, and then they mold the grads into their own image. No need to worry about crappy living conditions and pay, long hours, or any language barrier. For foreigners, you need to prove some SKILLS to go along with the LANGUAGE ABILITY. What makes you so unique other than having a Japanese wife?
Yes, some Japanese study abroad, but there are many who return to find that their companies don't want the foreign ways introduced into the works. Some live abroad (on transfers), and after they return they are given a long "cooling off" period of debriefing so they can readjust to Japanese ways of thinking and problem solving.