Japan's Supreme Court struck down the half-share rule for children born outside marriage in 2013, 18 years after upholding it

Article 900(4) of Japan's Civil Code gave a child born outside marriage half the inheritance share of a child born in marriage. On 5 July 1995 the Supreme Court Grand Bench upheld the rule in the case of a Shizuoka woman who died in 1988 leaving nine children born in marriage and one born outside it. Five justices dissented. A Tokyo man died on 25 July 2001 leaving three children born in marriage and two born outside it. The Tokyo Family Court, on 26 March 2012, and the Tokyo High Court, on 22 June 2012, applied the half-share rule. A Wakayama man who died in November 2001 left two children of each kind, and those courts did the same. On 4 September 2013 the Grand Bench ruled unanimously that the rule violated Article 14(1) of the Constitution, at the latest from July 2001. One justice stepped aside because he had run the Justice Ministry's Civil Affairs Bureau. The court said children should not be disadvantaged for circumstances they cannot choose. It also ruled that estates already settled by court order or agreement would not be reopened. The Diet amended the Civil Code on 5 December 2013, and the law took effect on 11 December 2013. Equal shares apply to estates opened from 5 September 2013, and to estates opened from 1 July 2001 that were not yet final.