The enso is a circle painted with a single brushstroke. Early Chinese sources such as the eleventh century Blue Cliff Record mention that Chan (Japanese: Zen) Buddhist masters often drew circles in the course of teaching. The circle is a symbol encompassing several possible meanings: in its completeness, it is a symbol of enlightenment; in its infinite nature it represents the cyclical nature of existence through life, death, and rebirth; and its empty center can be likened to emptiness, a fundamental concept in Buddhism.
Enso typically bear a brief inscription, either a phrase from a Buddhist text, a poem, or, as in this case, an invitation: Eat this and drink tea (Kore o kuite cha o maire). While the inscriptions on many enso liken the circle to the full moon, or to the void, these words suggest that Zen practice should not be divorced from daily life. The inscription connects the enso to everyday objects, a round teabowl or the round manju sweets that are often served with tea.
Each enso has slight variations that are thought to reveal the painter’s state of mind and character. Nantenbo’s circular line is bold, energetic, and forceful, expressing his personality.