Created by Fujio Akatsuka, Matsuyo Matsuno first appeared in *Osomatsu-kun* as the mother of the titular sextuplets. Loosely modeled after Akatsuka's own mother, she recurs across his works via the Star System, featuring in titles like *Akko-chan's Got a Secret!*, *Cat's Eye News*, and *Fujio's Waru Waru World*.

Matsuyo stands tall and slender, typically dressed in a dress or a long-sleeved top with a skirt and apron. Her design showcases short black hair flipped upward at the back, bangs, and large round glasses. Severe nearsightedness without her glasses leads to comedic situations, causing her to fail to recognize large animals like gorillas or lions. Her *Osomatsu-san* design incorporates a bun and pulled-back bangs, reflecting her middle-aged housewife status.

Her personality centers on her pragmatic, overworked role as matriarch. She is a no-nonsense, energetic figure managing her large family, frequently expressing frustration over financial and logistical burdens like food costs. Her practicality manifests in buying identical clothing in bulk for her sons to save money, inadvertently making them harder to distinguish. Moments of exasperation have led her to attempt having her sons adopted. Despite her stresses, she exhibits a mischievous and crafty side, orchestrating schemes involving her children or exploiting Iyami's insurance claims to break dishes near him. This duality extends to villainous family portrayals, highlighting the origins of her sons' chaotic traits.

Her relationships reveal deeper complexities. Matsuyo is devoted yet often feels overlooked, ignored while ill or forgotten during family activities. She experiences intense worry or grief if a child leaves home but can be unrelenting in defending them against mockery. A notable trait is her fondness for gold and jewelry, tempting her into extravagance when wealthy. In *Osomatsu-san*, her character evolves to address her adult sons' failure to launch; she pressures them to find jobs and move out while harboring a strong desire for grandchildren. Despite frustrations, she retains maternal instincts, occasionally babying her sons.

Trivia notes include early surname inconsistency, initially "Yamano" in one chapter before settling on "Matsuno." Her given name "Matsuyo" is rarely used in the original manga, mentioned only by friends in *A Wreck of a Class Meeting*.

Her development across media maintains core traits while adapting to narrative shifts. In *Osomatsu-kun*, she balances resourcefulness with maternal vulnerability. In *Osomatsu-san*, her role emphasizes the comedic tension between her expectations and her sons' NEET lifestyles, underscoring her enduring resilience amid ongoing domestic chaos.