Kōa Shōken 向阿證賢 (Bun’ei 2 / 1265 → Kōei 4 / 6 / 26 = 1345-07-26), late-Kamakura → Nanboku-chō Jōdoshū monk of the Seizan-Senjō branch 西山禪林寺派 (i.e. the Eikan-dō / Zenrin-ji sub-line of the Seizan school, founded by 證空 Shōkū’s disciple 淨音 Jōon). Native of Hyūga 日向 (modern Miyazaki); successor at Zenrin-ji 禪林寺 (Eikan-dō 永觀堂) in Higashiyama, Kyoto, as its sixth-generation abbot.
Kōa’s principal contribution is the Kōa sanbu 向阿三部 — the three-part Pure-Land vernacular doctrinal trilogy:
- Kimyō-hongan-shō 歸命本願抄 (KR6t0321), 3 fasc., on the Original Vow doctrine in senchaku form;
- Saiyōshō 西要抄 (KR6t0322), 2 fasc., on the Western-Pure-Land essentials;
- Fushi-sōgei 父子相迎 (KR6t0323), 2 fasc., on the welcoming-image of Amitābha and his attendants as Father and Son.
These three works are notable for their vernacular Japanese (wabun 和文) prose: unlike most medieval Jōdoshū scholastic literature (which is in literary Chinese / kanbun), Kōa wrote in vernacular Japanese designed for lay readership, making the Seizan-Senjō-ha doctrine accessible to a non-monastic audience and contributing significantly to the lay-Buddhist literary tradition of medieval Japan. The trilogy was widely circulated through manuscript and (from the Edo period) printed editions, and represents the mature Seizan vernacular Pure-Land doctrine.
Kōa is sometimes confused with the homonymous Ikkō Shōnin 一向上人 (the Jishū itinerant evangelist Ikkō Shunshō 俊聖, 1239–1287) on account of his alternate appellation, but the two are distinct: the Pure-Land Kōa is a Zenrin-ji school-monk, while Ikkō Shunshō was an independent itinerant.