In 'The Secret World of Arrietty', the tiny borrower girl is named Arrietty.
Arrietty is a young Borrower who lives beneath the floorboards of a human home with her parents, Pod and Homily. Borrowers are tiny people who secretly take small amounts of useful household items—such as sugar, tissue paper, and scraps—while trying never to be seen by the much larger humans who own them.
The story changes when Arrietty is discovered by Shō, a human boy staying at the house. Their friendship challenges the Borrowers’ rule that contact with humans is too dangerous. Arrietty is adventurous and curious, but she is also learning the practical skills needed to survive, making her first borrowing expedition with her father an important coming-of-age moment.
The film is a Studio Ghibli adaptation of Mary Norton’s 'The Borrowers' stories. Its original Japanese title is 'Karigurashi no Arietti', usually translated as 'Arrietty the Borrower'. The North American title emphasizes the hidden miniature society, while the heroine’s name remains the same in both versions.