Maru-chan is a French bulldog character and one of the main canine companions within the story. The narrative follows the everyday experiences of a young child living alongside multiple dogs, with Maru-chan featured as part of this central group. He represents one specific dog among others including Riku the Italian greyhound, Tsutomu the chihuahua, Yousuke the miniature dachshund, and Paguzō the pug. The story portrays their shared existence through ordinary interactions and domestic routines.

The character's background stems from the creator's personal life experiences with multiple pets. Maru-chan's on-screen presence reflects aspects of real-life canine behavior observed in a home environment. The portrayal focuses on the dynamics between the child and the assembled group of dogs, including Maru-chan.