Japan

The national flag of Japan, known as Nisshōki, is a base white flag with a large red disc (representing the rising sun) in the center. A legend says that its origins lie in the days of the Mongol invasions of Japan in the 13th century, when the Buddhist priest Nichiren was supposed to have offered the sun disc flag to the Emperor of Japan, who was considered a descendant of the sun goddess Amaterasu.