Ako, an administrative officer of the Disciplinary Committee, belonging to Gehenna Academy! As a capable assistant, she's always by Hina's side, working until midnight or all night, as if to say she's loyal to her beloved Chairwoman Hina. She looks like a knight in disguise.

An agent of the Millennium's secret organization, C&C. Her codename is "zero-three", an essential employee at "cleaning up". She is known by the nickname "Sweeper Master" for her ability to infiltrate enemy lines with a deceivingly tender impression and gracefully yet explosively "clean out" the enemy.