The Labour Standards Law was enacted on 7 April 1947 under Allied Occupation of Japan. According to its first article, it assessed 'the right of workers to live a life of human beings'. Its most distinctive clauses inhibit employers from summariliy dismissing workers and concluding short-term contracts. In addition, the law reinstated the prewar ban on night work for women and minors. It also introduced a hitherto unprecendented provision: female employees were granted monthly rest days for menstruation.
Read more? Sheldon Garon, 'Collective Labour Law in Japan since 1882' in The Rise and Development of Collective Labour Law (Berlin 2000)