Rumi Yokoi

Is a girl who sits right next to him during school and usually watches him kill time. She tries to look away but somehow always ends up mentally engaged in Seki's games. Sometimes Seki includes her in his games and attempts to kill time. She also tries to protect the weak in Seki's game using her eraser. She also scares Seki sometimes with her expressions. And sometimes Seki ends up thinking that she is a ghost. She also sometimes destroys Seki's creations on purpose and sometimes it's just a mistake resulting in Seki's glaring at her. She is also attached to the Robot Family and is always thinking about how Seki should follow their example. She also tries to save the Robot Family whenever she can and ends up taking them and not returning them to Seki till the end of the day so that the robot family is safe.

Unnamed Sister

Seki's little sister tries very hard to get Seki's attention but he just ignores her.