Sachiko, Princess Hisa was the second daughter and child of Emperor Shōwa and his wife, Empress Kōjun. Her personal name was Sachiko, and her title was Hisa-no-miya. Princess Shigeko was her older sister; her younger siblings were born after her death.

The Imperial House , also referred to as the Imperial Family and the House of Yamato, is the imperial family of Japan, consisting of those members of the extended family of the reigning Emperor of Japan who undertake official and public duties. Under the present Constitution of Japan, the emperor is "the symbol of the State and of the unity of the people". Other members of the Imperial Family perform ceremonial and social duties, but have no role in the affairs of government. The duties as an emperor are passed down the line to their male children. This Japanese monarchy is the oldest continuous hereditary monarchy in the world.