Mum's the word no longer.
Prince Hisahito of Akishino (秋篠宮悠仁親王殿下, Akishino no miya Hisahito shinnō denka) was born on September 6th, 2006 and is the third child of Prince and Princess Akishino, and their first son.
The Chrysanthemum Throne (菊花紋章; kikukamonshō or kikkamonshō is the common name given to the Imperial throne of Japan. The chrysanthemum (菊 kiku in Japanese) is the monshō, or crest, of the Emperor of Japan; therefore kikukamonshō literally means the Chrysanthemum Crest.
According to legends, the Chrysanthemum Throne is the oldest continuing monarchy in the world. In Nihonshoki it is said that the Empire of Japan was founded in 660 BC by Emperor Jimmu. According to tradition, Emperor Akihito is the 125th direct descendant of Jimmu. The historical record goes back to Emperor Ōjin who is stated to have reigned in the early 5th century. Despite the fact that there had previously been eight female Emperors (in Japan only the wife of an Emperor is called an Empress), under Japanese Imperial law (promulgated by the Imperial Household Agency and the Privy Council) women have been forbidden from reigning since the late 19th century.
The Emperor (Japanese: tennō; (天皇), "heavenly emperor") acts as a high priest in the ancestral religion Shintō, although his claim to divine origin from Amaterasu was formally renounced after World War II.
Under the provisions of the current Constitution of Japan, the Emperor is a "symbol of the state and the unity of its people"; he has no real political power but is the Head of State and a constitutional monarch.
(All the above was stolen from Wikipedia, I frankly couldn't give two whits about the whole thing.)
But on a personal note about Shintoism, my sister-in-law's grandmother was a Shinto high Priestess and more than 10,000 people attended her funeral in Toronto 15 years ago!