The national flag of Japan, Nisshōki or Hinomaru, is designated as the national flag in the Law Regarding the National Flag and National Anthem, which was promulgated and became effective on August 13, 1999.
Prior to this, it was designated as the national flag during the Meiji era, 1870. However, the history of the Hinomaru symbol is quite old and one can trace it back to at least as early as the early 7th century.
Since the GHQ occupation of Japan, the use of the Hinomaru was severely restricted by the Americans as of August, 1945. This restriction gradually loosened as years went by, but a strong stigma is still attached to the flag. It is often superimposed with the image of Japan as the aggressor and invader of Asia that was concocted and propagated by the US.
It is a rectangular flag with a height to width ratio of 2:3. A large red disc representing the sun is placed at the center on a white background.
There are two other national flags in the world that have a strong resemblance to the Hinomaru. One is the flag of Palau, which was adopted on 1 January, 1981.
It is a rectangular flag with a height to width ratio of 5:8. A large yellow disc representing the moon is placed slightly off-center towards the flag pole, with a blue background to represent the ocean.
The other flag is the national flag of Bangladesh, which was adopted officially on 17 January 1972.
It is a rectangular flag with a height to width ratio of 3:5. It consists of a red disc on top of a green field, offset slightly toward the hoist. The red disc represents the sun rising over Bengal, and the blood of those who died for the independence of Bangladesh. The green background symbolizes the lushness of the land of Bangladesh.
If the amount of the degree of off-center which 10%, the flag becomes height to width ratio of 3:5; identical to that of the national flag of Japan. The disc is significantly larger than that of the current Japanese flag.
Why are the flags of Palau and Bangladesh similar to Japanese flag? Is it just a coincidence? People can argue on this point. But, I would like to raise two facts which direct me to the opinion that the similarities are intentional rather than accidental.
The first is Palau. The battle of Peleliu is the bloodiest and most tragic battle where 10,675 Japanese people’s lives were lost defending the Island from US invasion, leaving only 34 survivors.
There are two large connections between Japan and Bangladesh. One is the battle of Imphal fought by British India and Japan against the British colonial forces. This was a crucial event which lead to the Independence of South Asian nations including Bangladesh.
The other connection is Justice Radhabinod Pal who was the only South Asian to be appointed to the International Military Tribunal for the Far East trials of Japanese war crimes. He submitted a judgment which insisted that all defendants were not guilty. As there was a requirement that all judges must be unanimous, no defendant should have been sentenced as guilty and hanged.