I had my own English school while I lived in Japan. I bought a small, already established, home English School with about 50 students in the suburbs of Yokohama, but I had to find my own place to continue the school.
I eventually rented a 2LDK apartment in a large apartment complex where most of the students lived.
We then went to the local city hall and registered for a small fee. The city assigned us an accountant at no cost for one year to help us with the business and we were in business. A very simple process.
Since we were a home-based business we did not need to be incorporated or a Ltd co and therefore, did not have the huge fees associated with it.
Seeing the "gold mine" that was around us, we then advertised with fliers in the local paper and, within a few months, had increased the students two-fold to about 100 as that was about all my wife and I could handle without hiring another teacher.
We charged 1,000 yen/hr per student for the 50 min lessons with a maximum of 10 students per class. Classes ranged from Primary schoolers on up to college students and business men. For private lessons we charged 10,000 yen per hr. I taught the conversation while my wife taught the grammer part for entrance exams and such. Do the math. It was great income.
We used two of the rooms for classrooms.
Overall, it was a great income and I never had to leave my home to go to work unless I had private students or when I taught in the mornings at a company.
The accountant was great as he taught us how to use the to laws to our advantage and we paid very, very little tax. (I think he wanted us to retain him after his year was up and we sure did!). Most of our rent was deductable as was the new car he convinced us to buy as a "business vehicle" with a magnetic mat on the doors advertising our school. Our trips around Japan were also tax deductable as they were "outings" with students! I don't know how he did it, but we banked alot thanks to him. If I were ever to do it again-and I might- I would use him again and go the same route!
I sold when the economy was going bust in the late 80's and returned to the US. The person I sold it to is still running it from a house he eventually bought in the neighborhood some 20 years later. Nice to see that the business I continued is still going strong!
Therefore, if you want to teach in Japan with your own business I recommend going the Danchi route and teaching out of your home as:
1. It's convenient, cheap, and costs very little to start up. We just purchased a few long tables with chairs and a white board and some books and some book cases.
2. In an area with many apartment buildings you have a ready-made clientele that would gladly walk a few minutes to your place than take a bus/train to a commercial school. Plus, for them, it's cheaper. That is if there are no other foreigners teaching in or near those apartments.
3. advertising fliers for the local newspaper are cheap and you can even deliver the ads yourself to each mailbox.
4. Once you're established and get a good reputation, word of mouth will spread and you'll be getting phone calls from people who heard about you from a regular student.
5. It's also great for businessmen as they don't have to travel a long distance from their home or pay outrageous fees to major schools for lessons. Saturday afternoons were best for them!
6. With an established teacher in the area who is not there short term, people will be more comfortable in that there will not be a different teacher every six months or so.
As Glenski mentioned, if you are single and do not have a sponsor it will be difficult as you will not be able to get a visa unless you will be working. If you are married and your wife is Japanese it will be a piece of cake.
If you are single, my suggestion would be to first go as a teacher with a teaching visa and begin searching out an area you'd like to settle in and teach. You will probably make some friends along the way who would gladly sponsor a responsible person.
Scope out the competition - the smaller schools and such in the area that is as the major big name schools will not be your competition. They are too far away and charge alot of money. Opt for the suburbs and not the big city. It's easier and the competition is far less. You can find Danchi's (large multi-building apartment complexes) everywhere in the suburbs.
Good luck and stay in touch.
