This artwork is a famous 19th-century Ensō (Zen circle) brushed by Taidō Shūfū (also known as Taidō Sōtō, 1776–1836), a prominent Rinzai Zen priest and the 444th abbot of the historic Daitoku-ji Temple in Kyoto.
The text written next to the circle is composed in Kanbun (Classical Chinese poetry used by Zen monks), paired with the artist's signature and seals.

The Poetic Text:

1st - Right Column: 透々日月賀 -Tōtō jitsugetsu ga
2nd - Middle Column: 独歩乾坤 -Doppo kenkon
3rd - Left Column: 紫野 諦道 - Murasakino Taidō

Literally translated: 
"The sun and moon shine through and through with joy;
Walking completely alone across heaven and earth."

In Zen literature, this poetic pairing translates more metaphorically to express absolute freedom, clarity, and spiritual enlightenment.

"With a heart permeated with innocence,
The virtuous dragon walks alone."

It signifies a state of mind that is completely transparent, pure, and unburdened by worldly illusions, navigating the vast universe in independent, peaceful solitude.