He was given the hoi of 'Keisan' ('san' means 'three' in Japanese), since he became a monk when he was 13 years old, in March (san-gatsu in Japanese) and on the occasion of the thirty-third anniversary.
13歳、3月、三十三回忌など「三」という数にまつわる因縁が深いため「景三」の法諱を与えられた。