Aiko Senoo (妹尾あいこ, Senō Aiko) is one of the main characters and the third Ojamajo, officially joining the group with Hazuki Fujiwara after they spy on Doremi Harukaze in the Maho-do. She appeared in Ojamajo Doremi and Power Friends. Aiko is from Tengachaya Osaka, who transferred to Misora with her father due to his work.
Aiko has fair skin and dark blue eyes with short matching hair ending at her shoulders with a flare. Her bangs are very short, exposing her forehead with a split on the right, where several tiny curls and a single, larger curl resides. Originally Aiko wore a green shirt lined in yellow with a pair of baggy, blue denim overalls.
In the first two seasons, it was rare to find both of Aiko's overall straps up.