Katsushika Ōi (葛飾 応為, c. 1800 – c. 1866), also known as Ei[1] (栄, or O-Ei (お栄) with the honorific prefix) or Ei-jo (栄女, lit.

It is rumored that their marriage ended as a result of Ōi's criticism of Minamizawa Tomei's work, claiming he was a terrible artist, and laughing at him for it.

[8] Neither of them cared about housework or maintaining their home, with all their time occupied by their work, both of them painting and printmaking alongside one another in an unkempt household.

Aside from drawing and painting, Ōi also made keshi ningyō dolls and sold them to earn a living.

[11] Few of Ōi's works are known: amongst them, a few nikuhitsu-ga paintings, the illustrations to the book Onna Chōhō-ki (女重宝記, 1847) by Takai Ranzan (高井 蘭山), and no prints.

The story tells of the outspoken O-Ei, daughter of the famed artist Tetsuzō (Hokusai), for whom she sometimes paints uncredited.