Born in 1573 in Izushi, Tajima Province (modern Hyōgo). He was ordained at ten and trained at the Rinzai headquarters Daitokuji, becoming its head priest at thirty-seven. In the "Purple Robe Incident" of 1629 he protested the shogunate's restrictions on imperial bestowals and was exiled to Dewa Province. Pardoned after three years, he won the deep devotion of the third shogun Tokugawa Iemitsu. At Yagyū Munenori's request he wrote Fudōchi Shinmyōroku, explaining the unity of sword and Zen, laying the foundation for spiritual discourse in martial arts. In 1639 he became the founding abbot of Tōkaiji, built by Iemitsu in Shinagawa. He died in 1645 at age 73. He is also traditionally credited with inventing takuan pickled radish.

A rebellious Zen monk who would not bow to power, yet possessed humor and warmth. His protest in the Purple Robe Incident showed monastic backbone; he remained composed even in exile. He had a practical intellect that applied Zen insight to daily life and martial arts.

Fudōchi Shinmyōroku remains a foundational text on the spiritual dimension of martial arts, influencing the philosophy of kendō and aikidō. Tōkaiji flourished as a major Shinagawa temple. The pickled radish "takuan" is named after him, leaving his mark on Japanese food culture as well.