Please tell me about paying national health insurance tax.

The National Health Insurance tax is calculated based on the gross income amount of the previous year, etc., and an assessment decision notification is sent to the householder in July every year. (If you join or withdraw in the middle of the fiscal year, the timing of notification may be delayed.)
If you wish to pay by bank transfer, please apply using the bank transfer request form. The bank transfer request form is available at the Inagi City Office/Branch Office.
If you wish to pay with a payment slip, please pay it at a financial institution, Japan Post Bank, a financial institution branch office in the city hall, or a convenience store within the deadline, as it is enclosed in the assessment decision notice.

For details on how to pay, please check the item "How to pay the National Health Insurance tax" on the "National Health Insurance tax" page.