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. It is shown they get married in the future
Jun-chan
Seki's little sister, Jun chan is very active and loves her elder brother a lot. She always tries to seek her brother's attention, but he ignores her most of the time. However, he is also very considerate of her and helps her a lot, just like when they went to the amusement park, he held her target for her to practice water shooting. Also, once Jun accompanied her brother in his class as she was feeling lonely in her kindergarten.