History of Japanese green tea
The first tea served in Japan was recorded in 805, when the two notable priests, Saicho and Koubou taishi have been back from China. The one established Enryakuji temple in Mount Hiei, and the other established Kongobuji temple in Mount Koya. The tea at that time was block-processed black tea. It is said that the Emperor Saga was fond of tea, and there is a record of cultivating tea in Gosho, the Emperor's dwelling in Kyoto. However, after the boom was over, tea has been forgotten. In 1191, the priest Eisai encountered matcha, powdered green tea in China - soong dynasty. This is the origin of current Japanese green tea, and tea ceremony has been developed along with zen philosophy.
This is the general history of Japanese green tea, but what we call "traditional" Japanese green tea is mostly for ruling class, such as samurai worriers or aristocrats, and folk tea is different.
Tea picking experience is available during May to July. Also, organic tea farm tours for foreign tea buyers would be more specific how to evaluate tea quality, differences between organic and conventional, and so on.