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. Zenj...