Jiun Onkō 慈雲飲光 (also called Jiun Sonja 慈雲尊者, 1718–1804), the foremost Japanese Sanskrit scholar of the late Edo period and one of the principal Buddhist reformers of the mid-Tokugawa era. Born in Osaka to a samurai-class family, ordained at the Hōraku-ji under Ninkō 忍綱 (a Shingon Risshū teacher in the 淨嚴 Jōgon lineage), and trained in Shingon, Vinaya, and Confucian studies. He founded the Shōbō-ritsu 正法律 (True-Dharma Vinaya) reform movement, an austere revival of monastic discipline, and the Unden Shintō 雲傳神道 syncretic Shintō school.
His magnum opus is the Bongaku shinryō 梵學津梁 — “The Ferry-Bridge to Sanskrit Studies” — a Sanskrit philological encyclopedia in approximately 1000 fascicles, the largest of its kind ever produced outside South Asia and the textual foundation on which modern Japanese Sanskrit studies (Nanjō Bun’yū at Oxford, Takakusu Junjirō at Berlin in the late 19th c.) directly built. The sōmoku-roku KR6t0422 is the table of contents and navigation guide for the encyclopedia. His comparative-philological methodology — Sanskrit-Chinese-Japanese phonological correspondences, systematic dhāraṇī analysis, attention to manuscript variants — anticipates much of modern Indological method.
The DILA authority id is A001258. He died at the Kōki-ji 高貴寺 (his final retreat in Kawachi) in Bunka 1 / 1804, age 86.