I am not a lawyer, but I recommend that your wife go through the procedure of status change; meaning, that she applies for a student visa (provided that she attends a properly certified language school) and stay in Japan under that visa. (I admit your company does not "send a request to Immigration to cancel your visa," though.)
The reason why I recommend this is because, though your employer might not notify Immigration of you leaving the company, and your visa is valid as long as you are employed, leaving a company is a major change in your circumstances, which by itself is a cause for status change requiring (properly) reporting.
Imagine what might happen if you and your wife kept the engineer and dependent visas, and:
- Next time you try to come back to visit your wife in Japan, they might ask you questions at airport immigration, something like "You've been away from Japan for XX months. Are you still employed by this company?" If you tell them there that you left the company, they might want to start an investigation/cancel your visa there immediately.
- Or, imagine your wife stayed in Japan alone to attend a school on her current visa, and she had to go to... let's say the city hall's alien registration section for some reason. They could ask her questions about whether you, the spouse, are here. Or other questions might arise concerning pension or health insurance scheme. That would create problem for your wife as well. I mean, it could mean "illegal stay."
Properly, dependent visa is for someone who needs to be in Japan together with the spouse/family as a dependent, so if you are out of the country on an extended period of time/if you no longer intend to be in Japan, she no longer qualifies for the dependent visa.
There have been questions asked here by non-Japanese spouse of a J and non-J couple, who goes through a divorce and asks if their current spouse visa is still valid until its expiratioin even after a divorce = a major circumstance change. Sometimes the answer is that he/she can stay till the end of the spouse visa (if that person intends to leave Japan for good in a while after the divorce), or change to another visa status before the current one expires (such as work visa/permanent resident visa) if that person wants to stay in Japan longer on his/her own.
Another thread about someone on spouse visa asking what will happen when he gets a divorce. It is similar to your case in the sense that it involves a major circumstance change. Replace "divorce" with "leaving the company" as you read it. Opinions seem to differ.
http://www.japan-guide.com/forum/quereadisplay.html?0+20695+... Maybe it is better if you can get someone to call Immigration on your behalf *anonymously,* not mentioning nationality or name, but just asking about proper procedures in general. So far as I search through this Forum, there seems to be no definitive answer given.
