Tsuen Tea is the oldest tea house in the world, founded in 1160 in Uji city, Kyoto Prefecture, Japan. It is also the 13th oldest company in Japan, and the 30th oldest in the world, appearing on the List of oldest companies.
Located across from Uji Station on the Keihan Uji line, just east of Uji Bridge (originally constructed in 646), successive generations of Tsuen owners provided tea to travelers as "bridge guardians." The shop is the subject of a Kyōgen farce called "Tsuen" and also appears in Eiji Yoshikawa's epic novel Musashi. Today it is operated by the 24th generation of the Tsuen family.
The founder of Tsuen was Furukawa Unai, a samurai vassal of Minamoto no Yorimasa. After retiring in his later years, Furukawa adopted the last character of his master's name (Masa), and called himself Tsuen Masahisa. He became a monk and took up residence at the east end of Uji Bridge.
His descendants carried on the Tsuen surname, serving as guardians of Uji Bridge, by praying for the durability of the bridge as well as the safety and health of the people who used it. As part of this role, they also served tea to travelers.
Various historical figures have been recorded as having tea at Tsuen, including the shoguns Ashikaga Yoshimasa, Toyotomi Hideyoshi, and Tokugawa Ieyasu. Today the shop sells tea products including the following: matcha – ground green tea, gyokuro – shaded green tea, sencha – whole tea leaves infused in hot water, karigane – contains also twigs of the tea tree, hōjicha – roasted green tea and genmaicha – mixed low – level green tea and roasted brown rice.
According to en.wikipedia