Aiko is a girl one year older than Shinichirou who attends a different school than her. She is going out with her best friend Miyokichi Nobuse.
But she may have feelings instead for Shinichirou hinted through a comment she made about if people can't become closer to the one they like, they'd like to get closer to the one closest to that someone. Aiko has known Shinichirou and Miyokichi since they were kids. She helps out at her family's Imagawayaki shop named Imagawayaki Ai-chan. She is shorter than Shinichirou but enjoys teasing him from time to time.
