Although it is widely known that marriage is one of the most certain methods to becoming a Japanese citizen, the effect is not immediate. Simply marrying a Japanese national does not automatically grant Japanese citizenship to a foreign national. Attaining Japanese citizenship must be done though the normal naturalization process and this process could take up to 3 years or more depending on the circumstances.
However, marrying a Japanese citizen does provide an immediate immigration benefit in that it allow the foreign national to obtain a spousal visa. This visa grants the foreign national the right to stay and work freely in Japan without limitations on what type of employment the foreign national may accept. Furthermore, although the visa must be renewed, there are no other time limits on how long the foreign national is allowed to stay in Japan. By staying in Japan on this visa, the foreign national may eventually meet the requirements to apply for Japanese nationality.
It should be noted, however, that the spousal visa is entirely dependent on the continued marital status of the couple. The visa can be terminated if the couple divorce, or even if the spouses cease to act as a married couple. For example, the foreign national’s visa may be in danger if the couple separate, even if they don’t file divorce papers.
While this system has the effect of keeping some foreigners in marriages for the purpose of maintaining their immigration status, the law is not intended to force foreign nationals to stay in an abusive marriage for the sake of a visa. In certain circumstances, it is possible to apply for a different visa or special permission to stay in Japan even if a spousal visa is terminated due to divorce or separation.