Soen was a disciple of Ekkei of the Myoshinji Temple, he traveled widely to learn from various priests. Also studied under Yukichi Fukuzawa, founder of Keio University.
He became Chief Abbot of the Engakuji Temple at the age of 33, succeeding Kosen. After attending an international religious conference in Chicago (1893) he made a round-the-world trip. Visited India to study Brahminism, then visited Korea and China before returning to Japan (1909). His distinguished disciples included Eiku Mamiya and Hogaku Seigo.