In the early Edo period, Tadazane OGASAWARA, who was the lord of the Kokura Domain, hired Ryowa FURUICHI, who was a descendant of Choin, as a sado (person in charge of the tea ceremony), and the school came to be called Ko school of the Ogasawara family (since the Chinese character for "Furu" [古] in "Furuichi" is also pronounced "Ko" in Japanese).
江戸初期、小倉藩主小笠原忠真が澄胤の後裔である古市了和を茶堂として召抱えたことにより、小笠原家古流と称する。