Originally, Greenery Day was the birthday of Emperor Hirohito (or Emperor Showa, the name bestowed after his death), who died in 1989. After his death, the holiday was transformed into a more national celebration of nature. This holiday has been celebrated on April 29 for many years, but in 2007, the holiday will be moved to May 4, the spot currently occupied by Between Day. April 29 will then be known as Showa Day.

Greenery Day was established to honor the Emperor’s love for nature, and Japanese people take this day very seriously. Hirohito was a vastly popular leader and was also the author of approximately 14 books on biology. He was the first “human” emperor of Japan, ending the belief that emperors were divine beings.