Women in Japan period to 100 days and allows any woman who is not pregnant during the divorce to remarry immediately after divorce. The Civil Code of Japan requires legally married spouses to have the same surname. Although the law is gender-neutral, meaning that either spouse is allowed to change his/her name to that of the other spouse, Japanese women have traditionally adopt their husband’s family name and 96% of women continue to do so as of 2015. In 2015, the Japanese Supreme Court upheld the constitutionality of the law, noting that women could use their maiden names informally, and stating that it
Double-barrelled name However, other combinations are legally possible. The wife may keep her maiden name ("nazwisko panieńskie") or add her husband's surname to hers, thus creating a double name ("nazwisko złożone"). A married man can also adopt his wife's surname, or add it to his. Polish triple-barreled surnames are known to exist; an example is the one borne by Ludwik Kos-Rabczewicz-Zubkowski, a university professor and writer, living in Canada. In Russia, double-barreled surnames are somewhat uncommon, but normal and accepted practice, often associated with some families of note wishing to preserve both of their lineages. Federal law #143-FZ "On Civil State Acts"