Meet the mischievously endearing 9-year-old known as Chibi Maruko chan. From outsmarting her grandfather to deliberating over spending her allowance, she navigates the world with the authenticity of a real child. As a new school term begins, Maruko finds herself grouped with two mischievous boys, reluctantly becoming their follower. The pressure of this dynamic weighs heavily on her at school. With the school's athletic competition on the horizon, Maruko joins her classmates in training, despite her occasional tardiness due to her laid-back nature. Through observing the intense rivalry between the two boys, Maruko discovers the depth of their unwavering friendship.