Naikan
Naikan (Japanese: 内観, lit. 'introspection') is a structured method of self-reflection influenced by Shin Buddhist principles. The term first appears in the work of the Shin Buddhist thinker Kiyozawa Manshi (1863–1903) to refer to a form of ethical and religious introspection. The practice of naikan was taken up by Kiyozawa's followers and developed in numerous directions.
Influenced by these modern developments, as well as by his experiences in ascetic practice, the Shin Buddhist cleric Rev. Yoshimoto Ishin (1916–1988) developed a form of therapy in the 1940s which he also called naikan.