Daizu is a male black cat and one of the two main feline protagonists in the anime. He lives in a household headed by an office worker in her thirties who has a great fondness for cats, and was the first cat chosen by the owner. His name is derived from the Japanese word for soybean.

In terms of personality, Daizu is characterized by a calm and serious disposition. He possesses an easygoing and relaxed nature, often described as being a glutton with a strong enthusiasm for food. A defining aspect of his character is his close attachment to his female companion, Azuki, whom he follows so consistently that he is practically considered her shadow. The cats in this setting are known for speaking with a Kansai dialect.

Within the story, Daizu's primary role is as one half of the central cat duo through whose perspective the daily life of the household is observed. He is a fixture of the home, which includes the owner's father, mother, grandfather, and an older brother whom the cats have nicknamed Megane, meaning glasses. The household also contains a Shiba Inu dog named Mamenosuke, who was adopted by Megane and, having been raised around cats, believes himself to be a cat.

His most significant relationship is with Azuki, a tricolor female cat who, despite appearing tough, is actually quite cautious and cowardly. Daizu's constant presence behind her creates a dynamic where he is a quiet, steady companion to her more anxious nature. He also interacts with the various human members of the family, such as the owner, Megane, and Moja, the owner's mother who dislikes cats, as well as the dog Mamenosuke.

The available information on Daizu focuses on his consistent personality traits and his role as a follower of Azuki, but does not provide details regarding any significant character development or change he undergoes throughout the series. Similarly, while his behavioral traits are well-defined, there are no descriptions of any notable, extraordinary, or super-canine abilities possessed by Daizu.