: As a prolific artist, Hakuin used bold calligraphy and painting as a form of "visual Dharma" to express the nature of enlightenment to both monks and laypeople.

: Hakuin revolutionized Zen training by systematizing the use of koans—paradoxical riddles intended to exhaust the logical mind. He is the creator of the famous koan, "What is the sound of one hand clapping?" .

Zen Master Hakuin Ekaku (1685–1768) is widely credited with revitalizing Japanese Rinzai Zen during a period of significant decline. His teachings, often referred to as "fiery and dynamic," are central to modern Zen practice.