Foreign couples that live in Japan are allowed to marry in Japan just as any ordinary Japanese citizen would be allowed to. The foreign couple needs to register their marriage at the local government office and both parties will need to submit a certificate of legal capacity to marry along with Japanese translations. Completing these procedures will legally marry the couple under Japanese law.
The only major requirement for keeping a spousal visa in Japan is to continue to stay married to a Japanese national. In general, spousal visas do not apply to couples who divorce or where one spouse has died, although it may be possible to switch to a long term visa in some cases. It is important to note that, even if the couple is legally married, they must also meet a certain standard of marital behavior and marriages that seem fraudulent risk the possibility of having a renewal visa rejected.
Under the citizenship by parentage system, as long as one of the child’s parents is Japanese, the baby is entitled to receive Japanese citizenship. The birth of the baby must be registered with the local government office or, if overseas, at the Japanese embassy or consulate. However, simply being born in Japan is not enough for a baby without Japanese parents to acquire Japanese citizenship.
There are two types of spousal visas in Japan, one for spouses of Japanese citizens and one for spouses of permanent residents of Japan, although both visas are substantially the same. Therefore, it is possible for a foreign national to receive a visa to enter Japan even if his/her spouse is only a Japanese permanent resident.