Traditionally, this day is associated with the story of Emperor Jimmu – the first Emperor of Japan, considered the beginning of the Japanese nation in ancient history. Despite its legendary nature, February 11th is still chosen as a milestone to remember and honor the long history of the Land of the Rising Sun. The fact that Japan's National Day is set on February 11th is actually a misunderstanding of the lunar and solar calendars. During the Meiji era, the Japanese government set the date to commemorate this important national event. This coincided with Japan's transition from the lunar to the solar calendar in 1873. The Meiji government then set the founding date as January 1st, 1873 according to the lunar calendar, which was January 29th, 1872 according to the solar calendar. However, people at the time mistakenly thought this was the Lunar New Year, instead of National Founding Day. Therefore, the government changed the founding date to February 11, 1873, after believing it had "accurately" calculated the date of Emperor Jimmu's birth, and since then, February 11 has become Japan's national day.

On this day, throughout Japan, flag-hoisting ceremonies, local celebrations, and events imbued with national pride take place. While not as boisterous as larger festivals, they are solemn and deeply meaningful.

For Hiroshima Energy Supply – a Japanese-owned business in Vietnam – February 11th is also an opportunity to appreciate the values that Japanese culture brings: discipline, dedication, precision, and responsibility.