My understanding was that it should be "no" too (no income then no resident tax), but apparently various members in our group (during our great debates), said that was not the case. It might also be a matter of where in Japan they are located. So looking into that.
1) It appears that part of the issue is when the person last received income. So any income into a tax year (example former job), results in resident tax. "When" they stopped working is very important.
Various foreigners appear to get caught up with this, and are "kind of surprised" by an unexpected resident tax bill. Probably because since they are unemployed at that time, it is more of a burden to pay the resident tax.
This of course makes sense (any income results in some amount of resident tax), but that wasn't the case being argued. Because what initiated the debate was a fully unemployed spouse with no income for more than a year.
2) Also any income by the spouse (example part-time job), will result in a resident tax bill
In fact, any "smallish" amount by the spouse in Japan, can result in a tax problem. As there is the avalanche of income tax, resident tax, health insurance (a different problem by itself), etc... There is a kind of sweet spot range from 1,000,000 yen (around 10,000 dollars) to 1,500,000 (around 15,000 dollars) or so, where the spouse has enough to pay off all the taxes and such, is still a dependent on the taxes of the other spouse (so they get an additional deduction), and it's considered worth it. Going beyond 2,000,000 (around 20,000) or so means another kind of trouble as they reach the point where the spouse can't be a dependent (no extra deduction) and must pay out more money into the national pension.
Again, in this case, this is not a truly unemployed spouse. Even smallish part-time income will result in resident tax. So this situation is understood.
3) Reverse sexism, targeting, or harassing married male foreign spouses in Japan
These interesting cases were brought up by male foreigners in the group, who had problems with immigration about being an unemployed spouse. In fact, such somewhat similar incidents appear to have been posted here on japan-guide too and other forums. After becoming aware of the issue, I have been spotting such reports on the Internet.
It appears that it's acceptable for a female spouse to be unemployed and at home. It usually stays as a non-issue and there isn't any income tax, resident tax, etc... expected by immigration officials.
If the foreign spouse is male and unemployed, then it suddenly becomes an issue. There is a demand for income tax, resident tax, and official explanation of why unemployed. Even the marriage visa or extension appears to be conditional to employment.
The clear problem with that would be what is the point of the marriage visa, if it's really a work visa to pull tax revenue for the state in disguise? Taking traditionalism out of the equation, why can't the male spouse be at home or unemployed?
In the case of two male members in the group, they stated that because of immigration they switched from marriage visas to work visas. One person going from work visa to marriage visa, back to work visa. This was because they were given only 1 year extensions despite being married for 3 years (in one case) and "harassed" about being unemployed. Switching to work visas also reduced the stress they had to put their wives through each year. Was quite surprised to hear that.