No one is sure about the origins of Japanese tea. Tea plants were already growing wild in Japan’s southern mountains long before the beginning of recorded history in the land. Such plants are called yama-cha 山茶 (mountain tea), and are sometimes used for non-commercial production today. While some claim that these tea plants have always been in Japan, their genetics are too similar to plants found in China for their continental origin to be denied. Nonetheless, since there are no records, we do not know who introduced them or when.
The earliest written mention of tea in Japan dates from the time of Nara (710-794), in particular, in documents from the Shôsô-in (正倉院文書) in Nara. However, the character used at the time, to 荼, also designates another plant, nigana (from the asteraceae family), so it is impossible to say for sure that the reference really was to tea.
The first certain record of tea in Japan dates from the beginning of the Heian Period (794-1191), and it employs the character cha 茶, freshly imported from China by the Tang Dynasty. According to the Nihon Kôki 日本後記 , in 815 the monk Eichû 永忠 returned from China with tea seeds and a production method from the Tang that probably corresponded to eicha 餅茶. (Eicha is tea made with leaves that are steamed, then crushed and dried in a mold, first in the sun and then over a fire. Next, the product is reduced to powder in a mortar, and then placed in boiling water. However, it should be noted that it is not matcha.) It is said that Eichû offered this drink to the Emperor Saga 嵯峨天皇 , who decided to popularize its consumption in the Imperial court. His reasons for doing so were most certainly a desire to do as in China, which was the model for Japan at the time. However, when interest in China waned in the second half of the Heian Period, this beverage was quickly abandoned, perhaps especially because it was not to people’s taste at the time. This kind of tea remained used only in a ceremony.