Kitayama Yūshōshi 北山友松子 (Chinese reading Běishān Yǒusōngzǐ, also written 丹水友松 Tan-suí Yūshō; Buddhist name Dōchi 道智; 1648–1719) — Japanese physician of the early Edo period, born in Nagasaki to a Chinese émigré father and a Japanese mother. He studied medicine directly under the Hāngzhōu jǔrén and Ōbaku Chán monk Dúlì Xìngyì 獨立性易 (= Dài Lì 戴笠, 1596–1672), who had fled to Nagasaki in 1653 after the Míng collapse. He later moved to Kyōto, where he became one of the most influential clinicians of the Genroku 元祿 era and one of the founding figures — together with Nagoya Gen’i 名古屋玄醫 and Gotō Konzan 後藤艮山 — of the Japanese kohō 古方 (“ancient-formula”) school, which rejected the LǐZhū 李朱 JīnYuán synthesis and returned to the Shānghán lùn 傷寒論 of Zhāng Zhòngjǐng as the basis of clinical practice. His principal surviving work is the Běishān yīàn KR3ep001 北山醫案.
He is referenced under the form “丹水友松” in the 1879 Huáng Zūnxiàn 黃遵憲 colophon to KR3ep002 Xiānzhé yīhuà 先哲醫話 as a patriarch of the Japanese return-to-antiquity movement.
CBDB has no entry; Buddhist Studies Person Authority (DILA) has no entry. Principal Japanese reference: Yakazu Dōmei 矢數道明, Kinsei Kanpō ijinden 近世漢方醫人傳 (Meiji Shoin, 1969).