The Japanese flag is one or if not, the easiest flag to recognize. It is so simple. It is just like a simple white rectangular cloth with a red circle at the middle. The Japanese refer to their flag as the sun disc or Hinomaru. The official name is Nisshoki which means the sun-marked flag.
The flag of Nisshoki was chosen by law as the national flag together with the selection of the national anthem on August 13, 1999. However prior to this, the Land of the Rising Sun had been using the sun disc flag as their default national flag for a long period of time.
In 1870, the government body of Japan called Daijō-kan published two proclamations during the early part of Meiji Era. The two proclamations made a stipulation on how the flag of the nation must be designed. In the third Meiji Proclamation no. 57 published on February 27, 1870, the Nisshoki was made the national flag of ships of trading. In Proclamation no. 651 published on October 27, 1870, the Hinomaru flag was adapted by the Japanese Navy. After the World War Two and during the earlier part of the American occupation, the usage of the sun disc flag was restricted. But later on the restriction was not strictly followed.
The theme of the sun disc flag was adapted by the daimyos and samurais in their banners during the early history of Japan. Eventually, the Rising Sun Standard of the Japanese Imperial Navy and the Hinomaru used the same symbol during the time of the Meiji Restoration.