You must register your address at your city or ward office within 14 days of moving into a municipality.
What you will need to register at your ward office:
Residence Card (Zairyu Card)
Once you arrive in Japan with legal permission for a mid to long-term stay, you will receive a Residence Card (在留カード, zairyū kādo) at the airport. You will need to register at your nearest ward office.
Bring your passport and shiny-new Residence Card with you to the city or ward office in order to register your address.
If you need to register your family members, do remember to bring your marriage certificate, your childrens' birth certificates and a Japanese translation for each document.
Resident registration (Jumin-toroku, Tennyu-todoke)
Those who are issued a Residence Card at the time of entry are required to report an address in Japan to a local ward/municipal office (Jumin-toroku) by submitting a prescribed form (Tennyu-todoke ) within 14 days from the date of arrival. The form (Tennyu-todoke) is available at the ward/municipal office.
Note: If you move within your ward, you need to report your change of address. And, if you ever move to a different ward, you must report this to your current ward office and then register in your new ward office within 14 days of moving.