Studying part-time with instructor visa?

This is kind of a hypothetical question but Google has completely failed me. Currently, I'm a full time teacher working for a private company, but I'm considering a return to education for a skill boost to improve my future prospects/get out of teaching. I want to study part-time in Japan but keep my full time job as a teacher here. Is this possible, or does my instructor visa prevent me from doing this? I don't want to revert to a student visa, otherwise I will lose my full time job. Information is tough to come by since this is not the typical way of doing things.

As I understand the rules as long as you work in the work allowed under your visa if you do additionally some unpaid activities such as studying thatfs not a problem. I went to language school (4 h/d) while on my work visa and while working and that wasnft a problem at all.

The other way round isnft possible. On a student visa you are allowed only some part time work.

Enjoy your life in Japan!

Thanks. I wouldn't really be looking at language school. I don't know too much about the course and whether its possible to study it part-time but for example, there is the MA in TESOL at Temple University. This is the kind of education I'm considering. I have a full-time job which supports me and allows me to do extra work if I want, but in terms of my visa I don't know if becoming a student at a Japanese university requires me to revert to a student visa to study there. I know I can't work full time with a student visa.

becoming a student at a Japanese university

1. Temple isn't a Japanese university. It is an American university, with a campus which happens to be located in Japan.

2. The answer to your question is no. You don't need to be on a student visa to be a student. However, many scholarships require applicants to have "student" as their status of residence. So, probably scholarships are out.

Other university services such as university-sponsored housing may require student status as well, but indeed studying itself does not.