Akira Kayama is a supporting character in Stellvia, first appearing as a friend introduced to the protagonist Shima Katase by the energetic Arisa Gennorth. Physically, she is described as a tall girl with green hair that reaches her chest and purple eyes. Her birthday is December 23, making her a Capricorn.

In terms of personality, Akira is initially characterized as a quiet and reserved individual. As the series progresses, however, she reveals a more perceptive and occasionally sharp-tongued side. During moments of group conflict, she demonstrates a keen ability to see through her friends' facades. She is not afraid to be blunt, such as when she confronts Arisa about running away from her responsibilities as a pilot and subtly indicates that Arisa's feelings for Shima are not as hidden as she believes. Akira also displays a snarky wit, as shown when she tells her best friend Yayoi Fujisawa that her attempts at subtlety do not conceal her true interests.

Akira's primary role in the story is as a member of the main circle of friends at the Stellvia space academy. Her motivations and internal struggles are grounded in relatable personal challenges. She suffers from a crisis of identity and a lack of confidence, as well as dealing with feelings of jealousy, which are portrayed as normal human experiences within the high-pressure environment of the academy. These personal issues form a key part of her character development, forcing her to confront her own insecurities. Her relationships are central to her character; she is identified as the best friend of Yayoi Fujisawa and is also the girlfriend of Joey Jones. While her specific piloting or technical abilities are not detailed in the source material, her enrollment at Stellvia implies she is undergoing rigorous training alongside her peers.