Owner, called Kainushi-san in the original Japanese, is a human character in the anime Mameneko. She is a woman in her thirties who works as an office lady and is a devoted cat lover. She is the one who brought the two cats Azuki and Daizu into her household and serves as their primary caretaker. She has brown hair and lives in a family home with her father, a company employee; her mother, a homemaker; her grandfather; and her older brother, a thirty-five-year-old office worker whom the cats call Megane because of his glasses.

Her personality is defined by a gentle, affectionate attitude toward animals. She genuinely enjoys having the cats around, looks after their needs, and puts up with the everyday mess and mischief they create. Her main motivation is simply to give Azuki and Daizu a safe and loving home, and much of her role involves feeding them, watching over them, and reacting to their behavior. Within the story she acts as the stable human center of the household, with the cats' daily adventures and the quirks of her family members all playing out around her.

Her most important relationships are with Azuki and Daizu, whose care is her primary responsibility. She is also connected to her family members who share the house with her. Her brother Megane later takes in a shiba inu named Mamenosuke after the dog's previous owner dies, which adds another pet to the household. Her mother is notably less fond of cats and is always looking for chances to get rid of stray kittens, which creates a mild contrast with the Owner's affectionate nature.

Because the anime is made up of short, episodic vignettes, the Owner does not go through a dramatic personal transformation. Her development is shown through her steady, patient routine and her enduring fondness for her pets rather than through major conflicts or changes. She has no special or supernatural abilities; her defining traits are her love of cats and her quiet, dependable care for the animals and people in her home.