Ichi-go ichi-e
History. The term can be traced back to the 16th century to an expression by tea master Sen no Rikyū: . Rikyū's apprentice Yamanoue Sōji instructs in "Yamanoue Sōji Ki" to give respect to your host . Ichigo () is a Buddhist term meaning "from one's birth to death", i.e. one's lifetime. Later, in the mid-19th century, Ii Naosuke, Tairō (chief administrator) of the Tokugawa shogunate, elaborated on the concept in "Chanoyu Ichie Shū": Great attention should be given to a tea gathering, which we can speak of as "one time, one meeting" ("ichigo, ichie"). Even  though the host and guests may see each other often socially, one day's gathering can never be repeated exactly. Viewed this way, the meeting is indeed a once-in-a-lifetime occasion. The host, accordingly, must in true sincerity take the greatest care with every aspect of the gathering and devote himself entirely to ensuring that nothing is rough. The guests, for their part, must understand that the gathering cannot occur again and, appreciating how the host has flawlessly planned it, must also participate with true sincerity. This is what is meant by "one time, one meeting." This  passage established the "yojijukugo" (four-letter idiomatic) form "ichi-go ichi-e" () known today. Interpretation and usage. "Ichi-go ichi-e" is linked with Zen Buddhism and concepts of transience. The term is particularly associated with the Japanese tea ceremony, and is often brushed onto scrolls which are hung in the tea room. The term is also much repeated in budō (martial ways). It is sometimes used to admonish students who become careless or frequently stop techniques midway to "try again", rather than moving on with the technique despite the mistake. In a life-or-death struggle, there is no  chance to try again. Even though techniques may be attempted many times in the dojo, each should be seen as a singular and decisive event. Similarly, in noh theater, performances are only rehearsed together once, a few days before the show, rather than the many times that are typical in the West, this corresponding to the transience of a given show.