Among them, the tayu of the Kanze school was the only performer who was allowed to have a special kanjin-Noh performance by the Edo bakufu (Japanese feudal government headed by a shogun) which could have only once in his lifetime, and this kanjin-Noh performance was called 'Isse Ichidai Noh' (literally, "a Noh play of one's lifetime"), 'Ichidai Noh' (literally, "one generation Noh"), or 'Gomen Noh' (literally, "approved Noh").
中でも観世大夫は、江戸幕府によって太夫一代一度限り許される勧進能を行う特権を持ち、これを「一世一代能」、「一代能」、「御免能」と称した。