Hello, I am Yoshi Tanaka of NILS Japanese language school. We have many new students for this April session from many countries around the world. They are confused by the different calendar system called gengo 元号.
Gengo was originally used in ancient China based on the idea that the emperor reigns time. It was introduced to Japan in the 7th century, when the first gengo “Taika 大化” was used. In Japan, emperors used to have the authority to designate the era and changed it frequently. Since the Meiji era, eras now only begin when a new emperor ascends the throne and end when he passes away. Gengo is also used to refer to the deceased emperor, for example, the late Emperor Hirohito 裕仁天皇 is referred to as the Showa Emperor 昭和天皇.

April 17th News, from NILS Japanese language school.