I want to move in from outside the city and take out Yokohama's National Health Insurance.

We take out National Health Insurance of Yokohama-shi from day when we moved in (it is not report date). Please submit the notification at your ward office Insurance and Pension Division National Health Insurance Section within 14 days.
If you send your new insurance card by mail to confirm that you live in Address, it will take a few days to arrive. If you plan to be consulted immediately, you will be issued a “medical certificate” as a substitute for your insurance card, so please apply at the ward office.

Note) Please come to National Health Insurance Section after completing the procedures for transferring your resident registration.

Insurance and Pension Division National Health Insurance Section, ward office in your ward

・Identity verification documents (My number card, license, passport, etc.) of the person to be notified

What is necessary for the procedure (don't forget to report in such a case)
Contact (Ward Office Insurance and Pension Division)