Arietty, a 14-year-old member of the Clock family, belongs to a lineage of miniature Borrowers who survive by discreetly taking insignificant items like sugar cubes from human homes. Standing 10 centimeters tall with shoulder-length auburn hair and black eyes, she dons a red dress for covert borrowing missions or a light brown blouse with a pale yellow dress otherwise. Driven by insatiable curiosity, she defies parental warnings to explore the garden and gather plants, her adventurous spirit clashing with their cautious worldview.

Her coming-of-age centers on her first borrowing expedition with her father Pod, a rite of passage shattered when Shō, a human boy with a life-threatening heart condition, spots her. This breach of secrecy forces her family to contemplate abandoning their home. Despite initial wariness, Arietty forges a tentative bond with Shō, who aids her in rescuing her mother Homily after the hostile housekeeper Haru exposes their dwelling.

Arietty navigates tensions between familial loyalty and burgeoning independence, evolving from a rule-abiding adolescent to one who challenges boundaries through her alliance with Shō and encounters with Spiller, a rugged Borrower boy from the wilderness. These relationships expose her to a broader Borrower society and deepen her grasp of survival, trust, and the precarious balance between her kind and humans.

The story culminates in her family fleeing Haru’s persecution. While the Japanese narrative leaves their future uncertain, the Disney adaptation hints at their successful relocation. Arietty’s journey transforms her from a sheltered youth into a resilient mediator who confronts existential threats, bridges species divides, and embodies the duality of her name—rooted in Greek and Persian words blending strength (“lion,” “eagle”) and fragility (“star,” “dainty”). Her bonds with family, Shō, and Spiller underscore her role as a connective thread between hidden and human realms, mirroring themes of resilience and interdependence.