International maritime signal flags is a set of specific signal flags used for visual communication between ships and vessels in the seas and oceans. These flags are used to broadcast the so-called International Code of Signals (MKS for short), which was approved in its current form in 1969. Most signals are 1 to 3 letters long, with each flag assigned a Latin letter. Moreover, each letter has been assigned a specific meaning. For example: a flag composed of two yellow stripes and one blue stripes is the letter D (Delta), which is assigned the meaning "Stay away - I am maneuvering with difficulty". On the other hand, the flag with two black and two yellow squares is the letter L (Lima) and means "Stop your ship!". However, the MCS also enables letter-by-letter communication, where the flags are assigned only a letter meaning, with no additional meanings.
The official flag of the Japanese state is called Nisshoki (freely translated: flag with the sun) or Hi no Maru (literally: round sun). The motif of the rising sun was probably placed on Japanese banners in ancient times, and it probably came to the country of the blooming cherry trees from China. It is likely that this motif was used as a flag to symbolize rulership over all of Japan at the end of the 12th century. On the other hand, for the first time, the "round sun" appeared on war banners during the civil wars in Japan at the turn of the 15th and 16th centuries. It is worth adding, however, that it was recognized as the official flag of the Japanese Navy only in 1854 - at the end of the Tokugawa shogunate, and just before the beginning of the Meiji era! During the Meiji era, Hi no Maru (white flag with a red sun) was recognized as the national flag, while the Imperial Navy used a flag called Kyokujitsuki, which symbolized the rising morning sun with its rays. It fought under such a flag in World War I and II. It is worth noting that now a twin similar flag is also used on ships of the Navy Forces of the Japanese Self-Defense Forces.