Dog of Flanders

Nello is a young poor boy who lives only with his grandfather and has a passion for art. He is friends with Aloise, who comes from a wealthy background and supports him in his artwork. They find and befriend a young beaten dog and name it Patrasche, who becomes a loyal companion to Nello. Despite the hard work and difficult times that Nello must face, he strives to become an artist like the talented Peter Paul Rubens.

Synopsis from Anime News Network