Leaving the Japanese school system but staying in Japan

Hello everyone, so I was brainstorming some future plans about living in Japan and I'd like some advice and insight into this idea I was having.

I got a placement from a recruitment company to be an ALT later this year and as exciting as it is, for a few factors such as income and work culture I started thinking about what if I'd like to leave the company but not necessarily leave Japan.

The idea I started entertaining was that perhaps I could work for this company for 2 or 3 years to put my time in and also fully settle into a stable living arrangement before I consider leaving. Then I would begin working online to generate income and earn in another foreign income with a stronger dollar amount than Yen.

I feel strongly about wanting to live in Japan but not necessarily working for a Japanese company.

I'd like to know if you have any ideas on how to flesh out such a plan and what kind of roadblocks or concerns you would have hearing this plan.