The National Flag of Japan
Flags showing the rising sun were used by some of the noted clan heads in ancient days. A record of these flags appears in annals written about 600 years ago. When the ban against building large vessels was lifted-after the advent of Commodore Perry's squadron in 1853-1854- the necessity arose to distinguish Japanese ships in foreign commerce, and the flag, as it now appears, was suggested as a national ensign by Lord Nariakira Shimasu, head to the Satsuma clan.
By official proclamation issued in January, 1870, the standard form and size of the flag were fixed in a rectangular proportion of 3 for the length and 2 for the width, with the diameter of the sun three-fifths of the width, placed in the center of the flag. The material, whether silk, cotton or muslin, was not stipulated. This ordinance was made to clarify the confusion then existing relative to the flag. The flag-staff universally used is of bamboo, painted black every few inches. It is capped with a golden ball.
The first display of the sun flag as the symbol of the nation was on the occasion of the trip to the United States, in 1860, of the first embassy every sent abroad by the government. It numbered 70 in all. The Powhattan, a steamship of the U.S. navy, was placed at the disposal of the Shogunate for this purpose. The ship flew the American flag at the stern, and the Japanese flag at the bow. In a national rite the flag was first used in Yokohama on the occasion of the opening of the first railway in Japan, by Emperor Meiji, on Sept. 17, 1982. The people of Yokohama, and those who lived along the rail line, hit upon the happy idea of displaying sun flags in front of every house in honor of the Emperor, and in celebration of the occasion.
Source: We Japanese: Being descriptions of many of the customs, manners, ceremonies, festivals, arts and crafts of the Japanese besides numerous other subjects. Fujiya Hotel. Ltd. 1950 version.