Oei, later known as Katsushika Oi, was born the third daughter of Edo’s talented painter Katsushika Hokusai and his second wife Koto. Although Oei became the wife of a town painter for a time, her love of the paintbrush more than her husband spelt disaster and she comes back home to Hokusai from the family she had married into. This is how Oei starts to help her father out in his painting of the “insurmountable high wall”. Meanwhile, Oei can only talk to the painter Ikeda Zenjiro, who is her father’s student, about her pain and worries. Zenjiro has taken Edo by storm as Keisai Eisen, the master of ukiyo-e portraying beautiful women. He visits regularly because he admires Hokusai and secretly likes Oei although their relationship is like childhood friends. Oei respects her father whose paintings fascinated her and continues to work as a painter who supports him behind the scenes. When Hokusai’s masterpiece Thirty-six Views of Mount Fuji was completed, she was also by his side.