text: Kaori Okuni, one of the women campaigning for change, said the ruling would lead to "suffering for those who plan to marry and those who are set to be born".
  Most women in Japan end up taking their husband's surname, a practice set to continue after Wednesday's ruling.
  But what do other countries do?
  In most well-populated countries, women are free to change their surname on marrying, if they wish. Many go further than that, putting in place laws stating that women do not have to change their names.
  France's law has been in place since the 18th century but, much like in Italy, there is some flexibility allowing wives to use their husband's surnames in an informal way. On all official paperwork, however, the maiden name must remain.
  The laws are much tougher in Greece and Quebec. In Greece, you must petition a court for a name change, and in Quebec, even if they wanted to, a wife cannot take her husband's surname at any point.
  In Iceland, women keep their maiden names after marriage. A surname is derived from a father's first name - so Bjork, Gudmund's daughter, becomes Bjork Gudmundsdottir - or, in certain circumstances, the mother's.
  A similar pattern is also followed in Ethiopia and Eritrea, where there is no concept of surnames as known in many Western countries. At birth, people are given one name, that is then followed by the father's name then the grandfather's name.
  Even after marrying, women retain their original three names.
  Could the Avatar actress Zoe Saldana and her husband Marco Perego - now Marco Saldana - be trend setters?
  The couple announced the move earlier this year, with Mrs Saldana calling her husband "a man who stood by change".
  In one case from 2012, however, a Mississippi man needed the help of the American Civil Liberties Union to take his wife's surname, having initially been prevented from changing the name on his driving licence.
  And in France, a change in the law now allows men to take their wife's surname - the first case was registered in Lyon in 2012, but only after seven attempts to do so were denied, despite the amendment.
target: Japan's Supreme Court has ruled that all married couples must have the same surname, despite concerns that the practice is discriminatory and archaic.