"Chi's Sweet Home" centers on a young kitten named Chi, who becomes separated from her mother and siblings after wandering away from her home. Lost and alone, Chi is discovered by the Yamada family, a kind-hearted couple with a young son named Yohei. Despite living in a pet-free apartment complex, the Yamadas decide to take Chi in, marking the beginning of her new life with them. The series chronicles Chi's daily adventures as she adjusts to her new environment, explores the world around her, and forms a close bond with the Yamadas.

The narrative is episodic, focusing on Chi's playful and curious nature as she navigates the challenges of being a kitten in a human world. From learning to use the litter box to encountering other animals in the neighborhood, Chi's experiences are portrayed with humor and warmth. The Yamadas, particularly Yohei, grow deeply attached to Chi, often going to great lengths to ensure her safety and happiness, even as they face the constant risk of being discovered by their landlord.

Throughout the series, Chi's interactions with other animals, such as the neighborhood cats and dogs, add depth to her character and provide insight into her growing understanding of the world. Her occasional longing for her mother and siblings is balanced by the love and care she receives from the Yamadas, creating a heartwarming dynamic. The story emphasizes themes of family, belonging, and the joys and challenges of pet ownership, all while maintaining a lighthearted and accessible tone suitable for readers of all ages.