He was born in Amagasaki in Settsu Province, a child of the Shimokawa samurai family. His grandfather had been a retainer of Katō Kiyomasa, but his father lost his post as a retainer of the Amagasaki domain and became a masterless samurai. The family was poor, and of eight children all but the eldest had to leave home to become monks or be adopted. Keichū was the third child.
Leaving home as a small child, he entered Myōhō-ji in Ōimazato village in Settsu and began studying under a monk named Kaijō. Though he became a monk because of family circumstances, his contact here with Buddhist scriptures and classical Chinese laid the foundation of his later scholarship. His studies at the temple nurtured a lifelong interest in words and books.
He went up Mount Kōya, studied under Kaiken of Tōhō-in and trained in Shingon. He is said to have received the rite of consecration and gained the high rank of ajari. Through this rigorous training he acquired a firm foundation as a monk. This is placed around this year, but views differ on the exact timing.
He became head priest of Mandara-in at Nishikōzu in Osaka. Around this time he became close to the poet and classical scholar Shimokōbe Chōryū and received much scholarly inspiration. Chōryū was a deep student of poetry and the classics, and this friendship became an important trigger that later led Keichū to study the Man'yōshū. Views differ on the timing.
Disliking a head priest's worldly duties, he traveled around the capital region and is said to have undertaken practice so severe at Hase-dera and Murō-ji in Yamato that he nearly gave up his life. He then stayed with Fuseya Shigekata and others in Izumi, reading many Buddhist texts, Chinese classics and Japanese classics, and also studying Sanskrit script. This is placed around this time, but views differ.
He received again a consecration transmitting Shingon teachings from Kakugen of Enmei-ji. After years of practice and reading in many places, he deepened his path as a monk. The union of deep Buddhist learning with wide reading of the classics became the force that later produced his original study of the classics.
He became head priest of Myōhō-ji, where he had studied as a child. It was from this time that he devoted himself fully to the study of the classics. He studied in turn the Kokin wakashū, the Tales of Ise, the Tale of Genji and the Hyakunin isshu, writing many commentaries and raising his name as a scholar.
Tokugawa Mitsukuni, lord of Mito, had asked Shimokōbe Chōryū for a commentary on the Man'yōshū, but when Chōryū could not complete it because of illness, his friend Keichū took it over. The first draft of the resulting Man'yō daishōki is said to have been finished around this time. The title means doing a master craftsman's work in place of Chōryū.
He completed the revised version of the Man'yō daishōki. He interpreted the Man'yōshū by a method of checking each point against old documents, and discovered regular rules in the use of words. In the same year, when his mother died at Myōhō-ji, he built the Enju-an at Higashikōzu in Osaka and moved there.
While trying to read the Man'yōshū correctly, he noticed contradictions in the kana spelling widely used at the time, and published the Waji shōranshō, which collected correct examples from classics such as the Nihon shoki, the Kojiki and the Tale of Genji. This spelling, called Keichū kana usage, greatly influenced the later formation of historical kana orthography.
He died at the Enju-an in Osaka. He is said to have kept teaching his disciples until his last day. His empirical method of seeking grounds in old documents opened the way for the later development of kokugaku by Kamo no Mabuchi, Motoori Norinaga and others. His grave is at the Enju-an, and in the Meiji era he was awarded a posthumous rank honoring his achievements.
Katō KiyomasaKamo no MabuchiMotoori NorinagaTokugawa Mitsukuni
Itō JinsaiTokugawa MitsukuniKaibara EkikenShibukawa HarumiTokugawa IetsunaIhara SaikakuSeki TakakazuMatsuo Bashō
People of the Edo period ・ People by period
Based on facts found in textbooks and biographies. Uncertain points are marked as such.