Foreigners living in Japan are required to create the My Number Card (individual number card) like Japanese residents.
You need to possess this card when wanting to work part-time or paying taxes.

★How to create My Number Card★
①An envelop with a notice card is mailed to you as a registered mail from the city hall/ward office of the place of your residence.
②Registered mail must be received in person by the recipient him/herself. If the delivery is attempted while you are away, a non-delivery notice is left to your door/mailbox.
(※Non-delivery notice includes contact information to request re-delivery, tracking number, etc. You need to call the contact number by yourself to have the mail delivered.)
③After you receive a notice card, paste a facial photograph to the card and submit it to the city hall/ward office. You will then receive an individual number card.
(※Because the card has your facial photograph, it can be used as a personal ID.)