Emperor of Japan
The current Emperor on the throne is typically referred to as "Tennō Heika" (, "His (Imperial) Majesty the Emperor"), "Kinjō Heika" (, "His Current Majesty") or simply "Tennō", when speaking Japanese. The current Emperor will be renamed "Daijō Tennō" (, Retired Emperor), often shortened to "Jōkō" (), upon his planned retirement on 30 April 2019, and renamed "Heisei Tennō" () after his death and will then be referred to exclusively by that name in Japanese. In Japanese culture, it is considered a major faux pas to refer to a living Emperor by his posthumous name, although the posthumous name is the same as the era, which is used in official documents.
Imperial House of Japan
There are currently 18 members of the Imperial Family:
The Princess Mikasa is the widow of the Prince Mikasa (2 December 1915 – 27 October 2016), the fourth son of Emperor Taishō and Empress Teimei and an uncle of Emperor Akihito. The Princess was born on 4 June 1923, the second daughter of Viscount Masanori Takagi. Princess Mikasa has two daughters and three sons with the late Prince Mikasa.