A stray bull terrier named Bow, easily recognized by the black circle around his left eye, finds himself temporarily living with a struggling manga artist. His life takes a turn when he is adopted by Sayaka, a cheerful third-grade girl whose father is a local yakuza boss. The father is initially furious and refuses to accept the accident-prone dog into their home, but he has a change of heart after Bow saves the life of his gang's leader.

The story follows Bow as he becomes a permanent member of the yakuza household, leading to a series of daily mishaps and comedic situations. He shares an especially antagonistic relationship with Sayaka's intimidating but often immature father, who grows jealous of the dog's popularity with his daughter. The narrative expands to include the rest of the neighborhood, with Bow interacting with other family members and pets, including a proud but clumsy Afghan hound named Shane and a massive, dim-witted St. Bernard named Sire. Over the course of the long-running series, notable developments include Bow falling in love, having a litter of puppies, and the personal growth and happy endings for the supporting human characters, such as the family's loyal bodyguard Sabu who eventually leaves the yakuza life to open a restaurant.