The true tea “boom” in Japan occurred in the Kamakura (1192-1333) and Muromachi (1336-1573) periods, which were marked by the warrior class’s rise to power.
In 1191, Eisai (or Yôsai) 栄西 (1141-1215), the Zen monk who founded the Rinzai School 臨済宗, brought back the seeds of a new tea and a new production method from Song Dynasty China. It was powdered tea that had been steamed to stop oxidation, which corresponds to what we now call matcha抹茶, the tea used in the tea ceremony. Today, we often think of matcha as typically Japanese, but it in fact originated in China. However, in the Ming period (1368-1644), shortly after it was introduced in Japan, it completely disappeared in China. This was the time of the development of green teas that were produced by subjecting the leaves to direct heat in a kind of large frying pan to stop oxidation, and then stirring and rolling them. This kind of tea was then steeped in a teapot before drinking. Japan thus became the custodian of a method for producing green tea using steam to stop oxidation, a method that is still used for the very great majority of Japanese teas, since it is used to make sencha.
In the Mirror of the East (Azuma Kagami 吾妻鏡), it says that after having established fushun-en 富春園, which is considered Japan’s first tea plantation, in Hirato 平戸, in what is now Nagasaki Prefecture, as well as other plantations in Kyûshû, Eisai offered his tea to the third Shôgun, Sanemoto 実朝, who was suffering from a hangover. It cured him.
It is said that Eisai also gave tea seeds to Myôe 明恵 at the Kôzan 高山 Monastery in Toganoo 栂尾, Kyôto. The tea from the plantations established by Myôe later came to be considered the most valuable, and were given the name honcha 本茶 (true tea, main tea).
In 1262, the monk 叡尊 from Saidai-ji 西大寺 monastery in Nara travelled to the Kantô area (where Tôkyô is now located), and apparently introduced tea to more than 10,000 people, according to Notes on a Trip to Kantô and Back (Kantô Oukan Ki 関東往還記). This can be considered the origin of tea production in those areas.
This tea was quickly adopted by monks, who found it to be a stimulant that could keep them awake during long periods of meditation, and also by the dominant warrior class. The latter engaged in kinds of blind taste test competitions called tôcha 闘茶, the goal of which was to tell high-quality hon-cha 本茶 teas from Toganoo in Kyôto from lower quality hi-cha 非茶 teas from other plantations.
It was also part of the basara 婆娑羅style, a kind of “show-offy” fashion trend in which warriors tried to outdo one another with colourful, flashy outfits and ostentatious attitudes.
Under Chinese influence, tea was often drunk sitting on chairs, but the introduction of the shôin-tsukuri (書院造) style of architecture led to tea drinking seated on tatamis. Such occasions were opportunities to display wealth and flaunt power. Finally, this style of architecture was simplified and purified to create the tea house used for the tea ceremony.