Mama is a middle-aged housewife standing 165cm tall with brown hair, big lips, and a short stature. She typically wears solid-colored t-shirts with pinkish skirts and an apron at home, though her attire varies across episodes. She originated from a family farm in Oita Prefecture, where she played with insects as a child and was strictly disciplined by her mother over minor matters. Her childhood nickname was "Banban," and she had a friend she hoped to marry, but ultimately entered an arranged marriage via omiai. After marriage, she and her husband ran an onsen in their hometown before relocating to a fifth-floor apartment in Tanashi, Nishitokyo, due to his job transfer.

Her personality centers on frugality and household management, driving an obsession for supermarket bargains that sometimes leads to physical confrontations. She despises rainy days, often serving expired ingredients to avoid shopping. Initially religious and superstitious, believing prayers brought good luck, she gradually abandoned these traits and softened compared to her earlier, meaner demeanor. She prides herself on a clean home and balanced budget but exhibits hypocrisy, refusing to admit her own faults like rude eating habits while criticizing others. Laziness manifests in frequent afternoon naps, snacking on senbei while watching TV, and neglecting chores on rainy days. She is caring yet terrifying when angered, with quick reflexes, and often agrees to conversations about unfamiliar topics, leading to awkward or embarrassing situations.

As a parent, she is stricter with her daughter, Mikan, prohibiting pierced ears, late-night outings, and extravagant fashion while prioritizing housework over studies. She dotes on her son, Yuzuhiko, allowing him leniencies denied to Mikan, though he resents her excessive attention and childhood nickname for him. Her hobbies include calligraphy, practiced under the pseudonym "Midori Imabari," and eating chikuwa. She socializes regularly with friends Mrs. Mizushima and Mrs. Toyama in their "Madam Déjeuner Club," often emulating the affluent Mrs. Misumi's lifestyle on a budget, sometimes embarrassing Misumi with their boisterousness.

Character development shows her evolution from a cautious, gentle new mother to a more careless, experienced parent. In the 3D film, she temporarily gains superpowers, causing chaos. In the Korean adaptation "Attamam'ma," her name was localized to Han Ae-Suk, and her family surname changed to "O" to align with Korean cultural context.