Japan's monarchy was once so removed from the public that in 1945, people were shocked to even hear Emperor Hirohito's voice when he announced the country's surrender in World War Two.
His son, Emperor Akihito, has overseen the transformation of the imperial household into a friendlier, more engaged symbol of the "unity of the people", as the role is defined in the constitution.
But age and ill-health have meant the emperor feels unable to continue in his role, and the government is allowing him to abdicate.
So here are 10 things you may not have known about Emperor Akihito's life and reign.
Japan Imperial family
1. He has a really long family history
Born 23 December 1933, he is the 125th emperor of a line which is traced back more than 2,600 years, according to official genealogies. That would make it the world's oldest continuing hereditary monarchy.
In keeping with ultra-formal royal tradition, he was raised apart from his parents in an imperial nursery from the age of two.
