Japan is the only nation where married couples must use the same surname. Critics say it violates women's rights and, unless the rule is scrapped, all Japanese could be surnamed Sato in 500 years.

Japan's falling population is owed, in part, to a spike in the success of women in the workforce. A greater percentage of Japanese women hold jobs than their American counterparts.

Japan's population has been shrinking for 15 years, with huge implications for the country's economy, national defense, and culture. Now, policymakers are working to boost birth rates.

Japan is staring down a demographic cliff. The population has shrunk for 15 straight years, with births hitting a record low of 730,000 last year and deaths a record high of 1.58 million. It now ...