Batako-san, also called Butterko, works as Uncle Jam's assistant in his bakery. She witnessed Anpanman's birth and helped raise him alongside Uncle Jam, forming a close familial bond. Her duties include baking, cleaning, laundry, and delivering goods. She is skilled in cooking and sewing, often mending or creating capes for Anpanman and other heroes to restore their abilities like flight.

She is consistently kind, caring, polite, diligent, and optimistic. Her appearance features rosy cheeks, black eyes, a small round button nose, and spiky black hair usually hidden under a chef's hat. She typically wears blue overalls over a white vest. An early concept showed her discovered as a baby in the woods by a young Anpanman, but this was replaced by her current role as an established bakery assistant older than Anpanman.

Her relationship with Anpanman has maternal elements, involving replacing his head during battles or when weakened and repairing his cape. She shares a strong bond with Cheese, the bakery dog, having named him and advocated for his adoption; she frequently interprets his barking. She interacts amicably with other heroes like Shokupanman and Currypanman, though these relationships are less prominent. A past narrative suggested a long-distance relationship with Omusubiman, though recent content does not explore this. Her connection with Uncle Jam reflects deep familial care and loyalty, though their specific origin story is not detailed.

Batako-san exists within the non-human realm of the Anpanman universe despite her human-like appearance. Her contributions focus on supporting bakery operations, maintaining hero equipment, and nurturing familial bonds within Anpanman's core circle.