Birthday: July 21st
Height: 168 cm (5'6")
BWH: 102/60/89
Rank: Middle-class Devil
Role: Queen
Race: Reincarnated Devil (Former Half-Human/Half-Fallen Angel)
Power: Elemental magic (mainly thunder), Holy Lightning (From Volume 5 onward)
First appearance: Volume 1

A third-year student and one of the "Two Great Onee-samas" of Kuou Academy along with Rias. Called the ultimate "Queen" by other members. Born between a human mother and fallen angel father, after the death of her mother, she became Rias' servant. She is a friend close enough to call Rias by her name in private, yet calls her Buchou in presence of others and displays a master-servant relationship in public. She persistently refuses to use her power of light, inherited from her father, but starts using it after being convinced by Issei.

After the events of volume 2, she begins to develop feelings for Issei, finally admitting those feelings to herself during the Occult Research Club's fight with Kokabiel. Afterwards, she begins to pursue Issei almost relentlessly, which tends to make Rias jealous for a while. She even proclaims that she's fine with being Issei's third girl, after Rias and Asia.

Though relations remain cool, Issei eventually convinces Akeno to begin opening up to her father.