"Miss Hokusai" is an anime film set in Edo-period Japan, centering on the life of O-Ei, the daughter of the renowned artist Katsushika Hokusai. The narrative explores O-Ei's struggles and achievements as a talented artist in her own right, navigating the challenges of living in the shadow of her famous father. Hokusai, a larger-than-life figure, is depicted as eccentric and deeply committed to his craft, often overshadowing O-Ei's contributions despite her significant skill. The story unfolds through a series of vignettes, offering glimpses into their daily lives, artistic endeavors, and relationships with those around them.

O-Ei's character is portrayed as fiercely independent and determined, yet burdened by societal expectations and her father's domineering presence. Her younger sister, O-Nao, who is blind and frail, lives in a separate residence, and O-Ei's visits to her reveal a softer, more compassionate side of her personality. The film also introduces other historical figures, such as the writer and artist Zenjiro, who becomes a close friend and confidant to O-Ei, providing insight into the artistic community of the time.

Themes of artistry, family dynamics, and the pursuit of creative expression are interwoven throughout the narrative. O-Ei's journey is marked by her efforts to carve out her own identity while grappling with the complexities of her relationship with Hokusai. The film does not follow a linear plot but instead presents a mosaic of moments that collectively paint a vivid picture of life in Edo-period Japan, blending historical context with personal and emotional depth. The interplay between O-Ei's personal growth and her artistic aspirations forms the core of the story, offering a nuanced portrayal of a woman striving to make her mark in a male-dominated world.