The national Flag of Japan was adopted on January 26, 1870, and officially recognized on August 13, 1999, following the passage of the Act of National Flag and Anthem. The flag is officially named the Kittenish, which means the sun-mark flag.This name refers to its appearance, which is a crimson circle set on a white background. flagsworld, A proper Japanese flag must have a height to length ratio of 2 to 3. Additionally, the circle must be placed precisely in the center of the white field and measure three-fifths of the length of the flag.