Sam is Lily’s older sister who is old enough to have a driver’s permit but is reluctant to drive due to their father’s death in a car accident. She is initially bitter about the move to Halmoni’s and struggles with the reality of Halmoni’s condition. By the end of the story, she becomes an ally to Lily.

Mom is Lily and Sam's mother, who is busy caring for her sick mother, Halmoni, while managing the move and their family. She is an accountant and finds a job in Sunbeam, and serves as a mentor to her daughters despite their occasional resistance.

Halmoni is Lily and Sam’s grandmother, who immigrated to America and settled in Sunbeam. She shares magical stories with Lily and is revealed to have brain cancer. As a mentor, she provides Lily with love, courage, and a sense of magic.

Ricky is a boy Lily meets at the library who becomes a steadfast friend to her. He is supportive and helps with Lily's tiger trap, remaining loyal even when she plays pranks like adding mud to his pudding.

Jensen is a teenage girl who works as a library aide and is a tutor for Ricky. She organizes events like bake sales and becomes friends with Lily and Sam, eventually becoming especially close to Sam.