An Anime film based on the manga of the same name, telling the story of the daughter of the very famous painter Hokusai. Trust me, you know Hokusai's work: he did The Great Wave off Kanagawa, possibly the most famous Japanese painting in existence. O-Ei (the daughter) was also a painter of some note, although she lived in his shadow for a long time. Much of the movie is about her relationships with her blind younger sister and her father. Much of it is also about how we see and process the world around us, and through that how it becomes art.
Like other good movies about the work of famous artists, it has been inspired by the work of the master it's talking about: some of the artwork is gorgeous. The movie is fairly low key as it's essentially a period character study. Some really beautiful moments, but ultimately only a good movie, not a great one.