Visa to participate in rising of child conceived outside of marriage.

I’m currently on WH visa. I’m a MALE. Some time ago I started dating that cute girl a while ago. At some point she got pregnant – sometimes that happens even if you try to avoid that ¯\\\_(ツ)\_/¯ . We decided to not terminate the pregnancy. Right now we’re considering different ways of me staying in Japan because of child that is yet to be born (after my WH visa expires, obviously).

I’ve made some research and it seems there are 3 possible visas that I could try to get:

* Working visa – it would probably take undefined amount of time to find a job that will sponsor a visa and let me work close to the child;
* Spouse visa – we would have to marry if I understand correctly. We would like to avoid that because marriage after few months is quite risky move, even for sake of child. We could of course get a “marriage articles” (is it a correct expression? is it a possibility in Japan?), but still;
* MAYBE dependent visa? But I could not partake a normal job if I understand correctly?;

As a temporary solution I can probably come on tourist visa, but it’s only 3 months stay, and repeated visits will probably attract the interest of immigration office and end in denying the entrance to the country. Not mentioning the work…

I tried to google if there are any other options but I’m out of luck finding results related to FATHER not mother.

So we wonder if there are any other options for getting a visa / residency status to participate in rising of the child?

The best outcome would be a visa that allows me to start sole proprietorship in Japan so I could continue to work as software engineer contractor for any company around the world.

In case you need more details:

* Engineer, Masters degree in IT;
* Worked as software engineer;
* Almost 8 years of work experience;
* Before I came for WH I used to make \~7000000 JPY/year before taxes in my home country, sole proprietorship; And I could easily get a much better or more contracts, not mentioning getting some “pocket money” from released games on steam and android play store;
* Male;
* Around 30 years old;
* Fluent in English and native in home language, basic Japanese (N5 maybe);
* The girl is Japanese national, has a bachelor degree and a stable, well paid job, few years of experience in her area of expertise;