[Sangetsu]

Technically you are qualified to teach in Japan. If you don't have a degree, you must have at least 3 consecutive years in the profession. A certification of some type would help immensely, such as a CELTA, or TEFL.

Though you can find employment without a degree, it is very difficult. All online employment advertisements will say that a degree is required, so applying online without a degree will disqualify you with no further consideration. Your only chance would be to come to Japan on a WHV and apply at schools personally.

You may need to explain to a prospective employer that you are able to teach in Japan without a degree due to your prior experience. The visa application process is more or less the same, but in place of your degree, you would need to provide tax or payroll records proving your employment history.

For those of you who are reading this and thinking "Wow, it is possible to get a job in Japan if you have three years of work experience!", this applies only to professions such as teaching, and not to vocational fields, such as car repair or construction, or service industry occupations.