A painter of the mid-Edo period and founder of the Maruyama school. Among his other art names were Kaun, Settei, Kaiun, Senrei, Rakuyo Sanjin and Osui Gyofu. Born into a farming family in Tanba province, he went to Kyoto and first studied under Ishida Yutei of the Kano school, learning Western technique on the side by painting pictures for optical viewing boxes; influenced further by Watanabe Shiko, he emerged in his early thirties as a rising painter of realism.

Works of this period include the handscrolls Both Banks of the Yodo River and Fortune and Misfortune. In his forties he brought together observation from life and the decorative manner, establishing an elegant decorative style built on a rational grasp of his subject, and produced the Bamboo in Rain and Wind and Wisteria screens. His late years brought the Pine Trees in Snow screens, the door panels of Daijoji, Kongoji and Kotohiragu, and his final work, the Hozu River screens.

The refined formal beauty and rationality of Okyo's painting won overwhelming support, above all among the townspeople of Kyoto, and transformed the character of painting in the city. Many painters gathered in his studio, and from them the Maruyama school was formed.