Items for which health insurance cannot be used:
Normal pregnancy and birth, abortions for economical reasons, health check-ups (ningen dock), vaccinations, cosmetic surgery, treatment for teeth alignment, injuries and accidents at work, acupuncture, moxa treatment (Chinese alternative medicine), massage (unless it is prescribed by a doctor), amenity bed costs, meals while in hospital, medical tests, operations, treatment and medication not covered by insurance.

Note 1 For details, ask a person who understands Japanese to enquire for you at your city, ward, town or village office, social insurance office or health insurance association.
Note 2 The information given is that confirmed as of July 2002. Note that a new system or system revisions may have been introduced after this date.

This information is from the CLAIR website. The Council of Local Authorities for International Relations (CLAIR) was established in July 1988 in response to rising concerns about local level internationalization in Japan.