Akeno is a girl of average height with fair skin. She has auburn hair that reaches her shoulders, and she normally leaves it down when not playing sports. When playing sports, she ties it in a low ponytail. She has gray eyes, which is the only trait she shares with her cousin, Himawari. She has a very expressive face, and she shows all of her emotions in her expression. She can most often be seen smiling. However, while playing volleyball, she can often be seen with a taunting smirk on her face, especially after she scores points or blocks someone.

She can often be seen wearing her school uniform, which consists of a white dress shirt, a black bow, a gray skirt, and black socks. She always wears shorts under her skirt. While playing for Inarizaki, she wore a long sleeve black and white jersey with maroon details and the number 6 in white, along with maroon shorts with white details. She normally doesn't wear knee pads when she plays. Her volleyball shoes are white with blue accents. Her casual clothes often consist of comfortable, yet stylish clothes with a trendy style.

Akeno is an enthusiastic and self-assured girl. She always tries her best, and she is very confident in her skills. She can be a bit overconfident, not thinking before she acts because she assumes things will go well. She can recognize where her weaknesses are, and she is not ashamed to seek out help to correct those weaknesses. She is good at looking at the positive side of things, and nothing ever keeps her down for long. She is good at shaking off personal failures. She is also very competitive, and she hates losing. Because of this, she can often get into arguments where she refuses to admit she's wrong. She can be quite stubborn, and she doesn't back down easily. Suna has called her pushy because of this.

She is very friendly, and she likes to talk to people. She is well liked by her peers because of her cheerful and outgoing nature. She likes to help people out when she can. She is quite playful, and she likes to tease and play harmless pranks on people. She can be pretty relentless with her teasing. She is very good at reading people, and she uses that to her advantage when she teases people. She likes to trick people, and some people have even said that she has a nasty personality when she tries to trick people. She likes to eat, and the amount of food she can eat surprises people. One of the ways she gets to know people is by asking what their favorite food is, and she considers it an important question.

Akeno was an energetic and rambunctious child. She grew up in Miyagi Prefecture with her older brother, Taisei, and her cousin, Osaki Himawari. While Himawari wasn't good at sports, Akeno and Taisei were, so that's often what they did when they were together. They played all kinds of sports. Akeno and Taisei even began playing on local teams, but Himawari couldn't keep up with them because of her lack of athleticism. Akeno excelled at almost every sport she played, and she never stuck with one sport for very long. Taisei, on the other hand, dedicated himself to baseball. When she was eleven years old, her aunt, Himawari's mother, died suddenly in a car accident. Himawari became withdrawn and pessimistic, nothing like the cheerful girl she was before. Akeno and Taisei were both very worried about their cousin, and they always tried to help her and cheer her up, but nothing seemed to work. Eventually, Himawari and her father moved to Hyōgo Prefecture to start a new life. Akeno was very sad about this, as she lost her favorite friend to play with.

Akeno continued to play every sport she could as she grew up. When she was in junior high, she played on her team's basketball team. After junior high, she attended Wakutani South High like her brother did. She joined the volleyball club. She was not very good at first, as she had never played competitively. However, she quickly learned the basics, and she began improving rapidly until she was even a starting player on the team. Her team defeated Karasuno High's girls' team in the Inter-high qualifiers, but lost to Niiyama Jōshi High after that. Instead of discouraging her, the loss only made her work harder to improve her skill. Seeing the incredible skill of Niiyama's ace, she dedicated herself to becoming the ace of her team and being a figure that her teammates could rely on no matter what.

After her first year of high school, Akeno and her family moved to Hyōgo Prefecture because of her father's job. She began attended Inarizaki High with Himawari for her second year. She was reunited with Himawari, and the two became close again. Akeno joined the girls' volleyball team at Inarizaki, and despite her lack of experience, she became one of the team's starting players. She was one of the team's top point scorers, giving the ace at the time a run for her money. She wasn't a very well-known player at her old school, but at this school, she was known as the incredible rookie player that proved that experience wasn't the only thing that made a player strong. However, her teammates just knew her as the volleyball monster that never stopped practicing and asking people to help her practice. She started to feel bad for asking her teammates to stay longer to keep practicing with her, so she began to ask players from the boys' team to help her practice. She first approached Miya Osamu, who was recommended to her by Himawari. He agreed to help her practice, and the two formed a friendship. With Osamu's help, Akeno improved even faster, and she became the ace of her team in her third year.

After graduating from high school, she moved in with Osamu. She tried out for the V.League Division 1 team, JC Miraculous, becoming an outside hitter. She joined at the same time as Kurogane Mitsuru and Shinohara Mai, and the three were seen as promising rookies that lifted the team to the top tier of the V.League Division 1.

• Her favorite food is mapo tofu.
• Current concern (2012): She has a hard time deciding what to eat for lunch.
• Current concern (2018): She has to start limiting how much onigiri she eats.
• Her star sign is Scorpio.
• Her worst subject is literature, and her best subject is science.
• Oguro (小黒) means "small, black," and Akeno (明乃) means "from the light."
• Her family name is derived from the Japanese name for a pale fox (oguro suna gitsune オグロスナギツネ).