Today, August 11th, is known as 'Mountain Day' in Japan. Some people insist that this day is related to the fact that the Chinese numeral "八" resembles a mountain, and that "11" also resembles the image of trees standing side by side, but this is only an ex post facto explanation. In Korea, April 5th is referred to as 'Arbor Day,' and in the past, events were held to plant trees in the mountains. As a result, bald mountains were successfully transformed into forested ones. However, this day is no longer a national holiday, and there are hardly any tree planting events. South Korea also temporarily assisted North Korea with its tree planting initiatives. The project aimed not only to provide North Koreans with saplings but also to teach them how to cultivate and maintain healthy trees and nurseries. Additionally, South Koreans traveled to North Korea to participate in tree planting activities.