Aki Hinata is the mother of Fuyuki and Natsumi Hinata and serves as the head of the household where the Keroro Platoon resides. She works as a manga editor for a magazine called Shonen Alpha, a job that demands much of her time and often keeps her away from home. Despite her busy schedule, she is portrayed as a calm, warm, and laid-back person who rarely shows anger or worry. She is athletic and highly skilled, possessing a black belt in aikido, which makes her the strongest member of the Hinata family in terms of combat ability.

Physically, Aki is a tall, attractive woman with long dark blue hair and teal eyes, and she is known for her curvaceous figure. Her typical attire includes a black shirt and white pants, often paired with a red biker jacket and gloves when she rides her motorcycle. On her days off, she prefers a green t-shirt and light purple shorts. Her age is a closely guarded secret, though she is estimated to be in her mid-thirties based on her children's ages and various time-travel episodes in the series.

In the story, Aki plays a crucial role as the accepting and unflappable authority figure. Unlike her children, she was not surprised by the appearance of Keroro, an alien frog, in her home. Instead, she was delighted, seeing him as a perfect source of inspiration for a new manga series. This decision is the primary reason the Keroro Platoon is allowed to live in her house. While she is generally kind to Keroro, calling him affectionate nicknames, she is also one of the few individuals he genuinely fears when she becomes displeased.

Aki has a unique set of quirks and motivations. She is fascinated by sticky and moist things, which contributes to her fondness for Keroro. Conversely, she harbors a strong dislike for animals, particularly vertebrates, which is her only notable weakness. This fear is so intense that she may scream or faint at the sight of them. Her motivation for allowing the aliens to stay is largely professional, as she constantly seeks interesting ideas for her work. She is one of the few characters who genuinely likes and gets along with Kururu, the platoon's cynical technical officer, and he has been shown to be concerned for her safety on several occasions.

Key relationships define her role. With her daughter Natsumi, she shares a mutual athleticism, though Natsumi can sometimes be jealous of the attention her mother gives to Keroro. With her son Fuyuki, she shares a closer resemblance in appearance and a warm personality. The identity of her husband and the father of her children is never explicitly revealed in the main narrative, remaining one of the series' ongoing mysteries. She is also the daughter of Akina Hinata, an even more formidable martial artist who is considered the final boss of the family.

Throughout the series, Aki experiences occasional development through unusual circumstances. In several episodes, Kururu uses his inventions to alter her age, turning her into a young child or a teenager. These events provide glimpses into her past and reveal that she has possessed exceptional physical abilities and a strong personality since her youth. Her own mother, Akina, often appears to help resolve these situations. Aki also demonstrates a surprisingly dangerous side when driving her motorcycle or car, earning nicknames for her reckless driving skills.

Among her notable abilities, Aki's aikido mastery stands out, allowing her to easily subdue opponents. She is also a skilled motorcycle rider, using her bike to navigate through traffic for work. While she is a competent cook and homemaker when present, her professional dedication as an editor is her primary focus. Her most significant ability within the story's context, however, is her open-mindedness and her talent for recognizing and cultivating interesting concepts, turning the presence of an alien invasion into a source of creative material for her manga.