Can the national health insurance tax in Japan be refunded?

If you work in Japan, your work unit may join social insurance together. If you resign, your national health insurance will be cancelled automatically. Otherwise, if you join the national health insurance, you don't have to pay the insurance premium of the national health insurance, but if you get sick or something, you have to pay your own medical expenses in full. If you have national health insurance, you only need to pay 30% of the full amount.