Salary amount required to get a work visa?

I am curious how much the salary would have to be for them to approve of the COE and the VISA? Would a 2.5 or 3 mil salary suffice? Or is there no real rule? I am curious because I would want to come help out my friend with his smaller real estate rental business (he has about 25mil in property owned) and I would help with IT related works and qualified with an IT bachelors degree. But I am curious what sort of salary would be required? I would be offered free housing and wouldn't need much money myself, so we were hoping he wouldn't have to pay me a big salary. I had read this is required to be at least 250,000 yen a month or more, which surprised me a bit as I had heard English teachers had gone there from other countries working on essentially slave wages, right? How exactly did they get a work visa then?

As far as I know:

This is an area where the Japanese immigration authorities do not provide a hard set rule, except to just say gat least equal to, or higher than, what a local person (Japanese) would earnh from that job, for engineer / specialist in humanities / international services visa.

So I would say (of course it depends on the job but) if it is below 200,000 yen a month or so, that would not be eligible. If your salary is 250,000 yen a month (sum of monthly base pay + bonus, divided by 12 months), then Ifd say it is sufficient.

I donft know what kind of gslave payh youfve heard of, but for English language teachers hired by so-called gEnglish conversation schools,h there once was a time when many native English speakers were attracted to those positions as a way to get into Japan, and businesses in Japan gave them less-than-decent conditions, including erratic/long hours, trying to get them to sell their teaching materials/study aids to the students, or where they took advantages of some applicants (for example those who grew up ginh English but not from Anglo-Saxon countries, etc.) and offered mediocre conditions.

there once was a time when many native English speakers...

and it still do till this day and getting worse day by day ... on paper/application purpose most were shown with pay salary of min.250k yen and yet actual truth is many are getting paid less than that.

'Slave salary' is dependent on where you come from .. but it is equivalent to Japanese fresh grad, and don't expect any increment.

most people(fresh grad) just suck it up(or being suckered) and use it as a stepping stone to get into Japan, to scratch their Japan itch or finding better job opportunity.