Is it necessary for foreigners to join the Japanese social insurance system?

As a general rule, any company that employs even one employee must join the social insurance system. Then are foreigners not allowed to renew their working visas if they are not enrolled in health insurance or employee pension plans? According to “the Guidelines for Changes in Status of Residence and Permission to Extend Period of Stay” announced in March 2009, from April 2010 onwards, foreign workers will be required to present the health insurance card at the counter of the Immigration Bureau when applying for permission to extend Period of Stay. However, this guideline has been further revised since 2010. It has been announced that “although the presence of a health insurance card at the counter is required, failure to present a health insurance card alone will not result in disallowance of the renewal of the period of stay. Therefore, if a foreign worker or employer does not have health insurance and applies for a work visa renewal or amendment, this alone does not mean that the work visa cannot be changed or renewed. However, the Immigration and Refugee Management Bureau does not publish any standards regarding the extent to which the presence or absence of social insurance coverage will affect visa changes or renewals. It seems that each case is judged on a case-by-case basis.