Lina is a 10-year-old girl adjusting to a new life in California after spending five years in China with her grandparents. She possesses a deep passion for drawing in her sketchbook and hopes to find an environment where her creativity can thrive. While she studied English in Beijing, she finds everyday American conversations daunting and struggles to communicate at school. She works hard to help her mother with a homemade bath bomb business.

Millie is Lina's seven-year-old sister who moved to California when she was two years old. She speaks fluent English, understands American social norms, and often steps in to translate or correct Lina's mistakes. She actively helps their mother run an Etsy bath bomb business by taking photos, mixing ingredients, and promoting products on social media.

Mom is a former amusement park engineer who attempts to support her family by selling handmade bath bombs online. She lost her salon job during the pandemic and struggles to afford their small apartment while waiting for her husband's green card approval. She changed her professional name to Jane to make things easier for American customers.

Dad is a trained microbiologist who currently works long hours on a regenerative organic farm. After losing a university laboratory position due to a prejudiced professor, he relies entirely on his current employer to sponsor his green card. He maintains a positive attitude and tries to teach his daughters that making mistakes is a necessary part of learning.

Pete runs the regenerative organic farm where Dad works. He is a gruff, demanding employer who insists his workers speak only English on his property. He holds significant power over the Gao family because Dad needs him to file paperwork for permanent residency.

Lao Lao is Lina's maternal grandmother who raised her for five years in China. Following the death of her husband, she relies heavily on Lina for daily assistance until Lina departs for America. She moves into a nursing home in Beijing, where she struggles to adjust to the cold rooms and lack of recreational activities.

Finn is a friendly classmate who shares Lina's desk in Mrs. Carter's room. He possesses a limited, food-based vocabulary in Chinese from a childhood au pair, which leads to awkward but well-meaning attempts to communicate. He copes with his parents' separation by reading graphic novels and sketching out his feelings.

Carla is a homeschooled girl who lives on Pete Burton's farm. She and her mother volunteer as part of an organic farming program in exchange for basic room and board. She misses drawing and baking with her late father and quickly strikes up a supportive friendship with Lina and Millie.

Mrs. Ortiz is an ELL teacher who works with Lina to build her confidence in speaking and reading. As an immigrant from Guatemala, she shares her own early struggles with the English language to make Lina feel less alone. She uses imaginative games to help her students learn and process difficult emotions.

Jessica is a classmate of Lina's who frequently mocks her English skills. She boasts about her artistic talents and complains audibly when Lina attempts to read aloud in class. She relies heavily on her mother's influence within the school's fundraising group.

Mrs. Carter is Lina's main classroom teacher. She tries to create an inclusive environment, praises Lina's artistic talent, and facilitates class read-aloud sessions using diverse books like Flea Shop.

Mrs. Hollins is the school librarian who provides a safe haven for Lina during lunchtime. She introduces Lina to graphic novels, which help bridge the language gap through visual storytelling.

Mrs. Scott is Jessica's mother and the head of the Blue Patrons, a school fundraising group. She holds strict views on what constitutes appropriate reading material and believes immigration topics do not belong in the classroom.

Mrs. Muñoz is Carla's mother. She works long hours on Pete's farm in exchange for room and board, struggling to provide for her daughter following the death of her husband.

Mr. Beezley is the landlord of the apartment complex where the Gao family lives. He strictly enforces rent collection, adding to the family's financial stress during a difficult economic period.

Lao Ye is Lina's late grandfather. He helped raise Lina in Beijing before passing away a year prior to her move to the United States.

Hazel is a popular girl in Millie's class whose mother is a TikTok hair influencer. Millie frequently tries to gain her approval and secure invitations to her exclusive social events.

Rosa operates a local taco truck and lives near the Gao family. She kindly allows Mom and Lina to use her commercial freezer when they need to quickly set a large batch of bath bombs.

Virginia is Pete's former wife and the author of several books on progressive farming techniques. Her past with Pete involves a shared tragedy that still influences his behavior.

Nate is a rude classmate who mocks Finn for associating with Lina, labeling her as a foreign exchange student in a derogatory manner.

Preston is another classmate who participates in mocking Lina. He later demands she teach him a phrase in Chinese to impress girls.

Mallory is a classmate of Millie's who becomes a genuine friend to her, shifting Millie's focus away from seeking the popular crowd's approval.