Miss Hokusai is a anime about Katsushika Oi. Born O-Ei (Anne Watanabe) and her life as an artist during the Edo era in Japan. Her father Tetsuzo (Yutaka Matsushige), is a famous artist that works under the pseudonym of Hokusai. Hence the title.
Her life is like that of a traditional apprentice. She learns her trade and works under her father’s name. She doesn’t sign any of her own works because as great as she is, she is still Tetsuzo’s student. And it isn’t until the end of the movie that Tetsuzo tells her that she should think of an artist name. Meaning he has deemed her worthy enough that she should sign her own works.