•If someone who should appoint a tax agent does not file the notification, the tax office can require them to do so, or ask in writing that a convenient party with an address or residence in Japan act as their tax agent (a designated tax agent). A designated tax agent only receives and forwards documents - they do not file returns or pay tax on your behalf
•If you have rental or real estate income in Japan, you must continue filing tax returns as a non-resident even after leaving
•The tax agent can be a corporation or an individual, but must have an address or place of residence in Japan and be conveniently placed to handle the work (Act on General Rules for National Taxes, Article 117(1)). They should preferably be based within the area covered by the tax office for your place of tax payment
•To change your tax agent, first file a notification dismissing the agent you already registered, then file a notification appointing the new one