Maintaining Visas, paying your own salary?

Hello,

My friend is looking to open a rental business. In total there will be about 25mil yen in capital in the business at the start. He would like to be on the business manager visa and bring me on as an employee under humanities visa (I have an IT/Communications degree)

Critically, he has 50k$ guaranteed from the military from disability every year that he is going to invest further into the company.

Obviously owning 25mil yen in property in Japan at best could probably net a 10% ROI and likely even lower even if you do a good job. 2.5 mil sales would certainly not pay our salaries, so we would be in the red for a few years technically.

My question is, since it would be inevitable to run at a sales to salary loss for the first few years, do you think its fine so long as we are funding our own salary with investment and can consistently prove every year that the investments into the company exceed our salaries and the capital is growing?

Being critical - If you are doing a business manager visa and have to come to a forum to ask a basic question like this, I would imagine the Immigration assessment will look pretty closely at the business plan you submit.
Being generous - yes, you can pay salaries out of the capital you use to establish the business, but if you are not making profit, expect renewal of the visa to be difficult and potentially declined. They have a set of quite probing questions they will ask.

You should consult a visa lawyer with those questions.

In some prefectures (I think Fukuoka being one) they have special investor Visa for people looking to start a company there. But it has strict requirements. As far as I can remember you need to invest a certain sum in your company (It was something like 60-100k€ equivalent) and after a year or two you need to either hire a japanese employee or proof of a certain amount of profit (or revenue?).

I don't think you can just randomly show up and open a business without any requirements as a foreigner... It doesn't matter how much money you have.