Ensõ (circle) is a sacred symbol in the Zen school of Buddhism. Ensõ symbolises many things: strength, elegance, the universe, the state of mind of the artist at the moment of creation and the acceptance of imperfection as perfect, the spirit of harmonious cooperation, the visible and the invisible, absolute fullness in emptiness, the circle of infinity and the cyclical nature of existence.
Hanshan was a legendary figure associated with a collection of poems from the Chinese Tang Dynasty in the Daoist and Zen tradition. He lived in a cave named 'Hanyan' ("Cold Cliff") in the Heavenly Terrace (T'ien T'ai) Mountains. Most of Hanshan's 600 poems were inscribed on tree trunks or rock faces, or written on the walls of caves or houses. Hanshan's evocative poems drew heavily on Buddhist themes, often remarking on life's short and transient nature.