Chibi Maruko-chan, a playful and mischievous 9-year-old, prefers to go by her cute nickname. She delights in playing pranks on her grandfather, navigates the struggles of managing her allowance, and shuns sitting next to boys she considers unattractive. Despite her quirks, Maruko is just like any average child with her own thoughts and emotions. At the beginning of the second term, Maruko reunites with her classmates and is placed in a group with two rambunctious boys who assert their dominance over her, leaving her feeling overwhelmed by the school's expectations. As the excitement builds for the school's upcoming sports competition, everyone is preoccupied with preparing themselves. Maruko strives to maintain her workout routine despite her inclination to procrastinate. She discovers that the two boys have a close bond but are always competing against each other.