Mai Kasai 葛西舞
A girl who moved from Tokyo to the countryside at the beginning of the series. She lives with her parents and younger brother, but she barely talks to her family members.
In middle school, she adopted the goal to get through her remaining childhood as smoothly as possible, until she can become independent. For that goal, she generally tries to stay out of trouble. She barely talks to her family members, because this could mean getting into a fight. She keeps her grades always slightly above the average, in order to not stand out and avoid trouble with teachers and family. She gets on good terms with the influential members of a class and ignores the rest, without actively promoting any actions. Generally, Mai asseses her situation and the people around her and selects tactics that allows her to proceed in a smooth fashion.