Yuán Chāngkè 原昌克 / Hara Masakatsu (hào Nányáng 南陽 / Nan’yō, 1753–1820), Edo-period Japanese physician of the Tokugawa late-18th to early-19th-century period. Native of Bushū 武州 (modern Saitama). Best known for the eight-juan Jīngxué huìjiě 經穴匯解 (KR3ee022) of Kyōwa 3 (1803), a critical-philological synthesis of Chinese and Japanese acupoint-literature. Also author of the Cóngróng lù 從容録 (case-records) and other Japanese-language acupuncture works. His maternal uncle the “Dànyuán” 淡園 elder had drafted an earlier two-juan version of the Huìjiě; Hara expanded and re-sourced it after the uncle’s death. Catalog meta classifies him under 清 (denoting his Chinese reception); in Japanese sources he is classified as Edo-period.