Akane Kawashima is a supporting character in Blue Drop. She is a student at the same school as the protagonist, Mari Wakatake, and is a resident of the Aoumi House dormitory, where she lives alongside Mari, Hagino Senkouji, and Michiko Kouzuki. Unlike her peers, Akane has been retained for an additional academic year due to unspecified domestic circumstances at home, making her an upperclassman to the other girls. Despite the challenges in her home life, which have influenced her personality, she has grown into a dependable and supportive senior figure. She embodies the archetype of an onee-san, a reliable older sister figure to those around her.

Akane has a cheerful and consistent daily routine, most notably her unwavering dedication to drinking milk every day. Her primary passion and motivation lie in the culinary arts; she frequently indulges in cooking and harbors a clear ambition to become a professional cook. This aspiration is demonstrated when she treats Mari and Michiko to lunch in town, using the opportunity to reveal her career goal and to offer gentle advice. In this scene, she encourages the more reserved Mari to be more open and honest in her relationship with the mysterious Hagino, showing her perceptive and caring nature. Her role in the story is primarily that of a supportive confidante and a source of normalcy and warmth within the Aoumi House, contrasting with the more complex and secretive affairs involving the alien Arume. There is no available information on any notable abilities beyond her domestic skills or on a significant character arc or development throughout the series.