When the applicant took up a new job
Activities a foreign national can engage in Japan are determined by his/her given visa. When you took up a new job, you need to prove to the Immigration Bureau that activities you are engaged in are still within the scope of your visa.
In fact, renewal of a working visa where you took up another job is similar to making the visa application for the first time.
Furthermore, once the Immigration Bureau decides that the job you are engaged in is not within the scope of visa, you may have to leave Japan if you cannot find another job you are eligible to engage in.
If you wish to renew your visa without having to worry about such consequences, you can apply for a Certificate of Authorized Employment (Shuro Shikaku Shomeisho) before you take up a new job.
A Certificate of Authorized Employment is issued by the Immigration Bureau to show your prospective employer that you are eligible to engage in the such activity.
Alternatively, if you have already taken up a new job, it is still beneficial to apply for a Certificate of Authorized Employment. Even when your application for a Certificate of Authorized Employment failed, you can still remain in Japan and look for another job that is within the scope of your visa during the period of stay.
However, when the immigration Bureau declines your application for renewal, you would most likely be designated a period for departure of 1 month. And within that 1 month, you need to find a job that matches your visa eligibility.
If you are thinking to take up a new job, or you already have taken up a new job, feel free to consult us so that we can advise you whether and how to make application for a Certificate of Authorized Employment!