The red disc, known as the 'Hinomaru' (Circle of the Sun), represents the sun. Japan is historically known as the 'Land of the Rising Sun,' and the sun goddess Amaterasu is said to be the ancestor of Japan's emperors.
History
The Hinomaru has been used as a symbol for centuries. It was officially designated as the national flag in 1870 for merchant ships and formally adopted as the sole national flag in 1999.
Construction
The flag has a 2:3 ratio. The red sun is exactly in the center of the white field, with a diameter that is three-fifths of the flag's height.
