In Japan, everyone is required to enroll into medical insurance to ensure easy access to medical care. The National Health Insurance is one such medical insurance plan, and is administered by the prefectural and municipal governments where you live.
The National Health Insurance is for people who are not covered by company health insurance. Foreign nationals must also enroll into the National Health Insurance if they are listed in the Basic Resident Registration and are not covered by their company’s health insurance.
Even if their initially expected period of stay in Japan at the time of entry is less than 3 months, they must enroll in the National Health Insurance if they later expect to stay in Japan for 3 months or more.
Please note that those who are here for tourism purposes are not allowed to enroll into the National Health Insurance (even if they stay for more than 3 months).