Starting side-business on teaching visa

Hi, I searched the forum for details on this, but couldn't find a thread about the same situation.

I am currently working in Japan as a teacher, on a Specialist in Humanities visa. I have no intention of quitting this job, so I can maintain sponsorship.

But I have an idea for starting a small side-business that has nothing to do with teaching. It would be done in my free time, and can be done from home with my computer.

There are 3 points that I need clarification on:

1. Is it legal for me to run the side-business on my visa?

2. Are the tax issues simply a matter of me adding the business profit to my teaching income, and reporting it at the tax office?

3. Can I do this without registering as a company?

I think the answer to all of these questions is 'Yes', but I want to see if anybody knows for sure, before I march into the tax office and admit running an illegal business. :-)

Thanks for any advice!

To 1., I actually don't know the answer.

You might want to find out from your employer if they allow any side jobs. Some Japanese employers I know do not allow this.

For taxes, if your income from your side businesses goes over a certain limit (I think it was 200,000 yen), you will need to do your own tax returns (tax filing procedures) instead of the company taking care of it all (I assume so, currently?).

My employer is cool with the business. They think it's a good idea and have been encouraging me to pursue it!