Yuki is an 11-year-old Nisei girl who lives a comfortable, ordinary life in Berkeley, California. She possesses a deep fondness for animals and treats her pets almost like people. As her family faces forced relocation to concentration camps, she attempts to understand the sudden prejudice directed at her community. She tries to maintain her optimistic spirit and adapt to the harsh conditions of the internment centers.

Ken is Yuki's 18-year-old brother and a student at UC Berkeley with ambitions of becoming a doctor. He is an active student and a star player on the Japanese Students Club basketball team. When the government arrests his father, Ken must immediately register as the head of his family. This premature thrust into adulthood tests his patience and challenges his strong sense of justice.

Mrs. Sakane is a gentle Issei woman who serves as the level-headed matriarch of the family. She immigrated to the United States to marry her husband and maintains many traditional customs in her household. She is an accomplished poet, a passionate gardener, and a generous host. She works diligently to preserve a sense of dignity and home for her children inside the uninsulated barracks.

Mr. Sakane is a prominent Issei businessman and community leader in Berkeley. Though legally barred from obtaining American citizenship, he is a patriotic and law-abiding resident. His community influence makes him an immediate target for arrest following the Pearl Harbor attack. He possesses a diplomatic nature and consistently seeks to improve living conditions for his fellow prisoners.

Mr. Toda is an elderly Issei bachelor and a long-time friend of the Sakane family. He frequently visits their home in Berkeley and acts as an extended family member. Facing the harsh realities of the internment camps, he experiences feelings of betrayal. He finds himself caught between his affection for the United States and his Japanese heritage.

Emi is a young orphan girl who lives with her grandparents. She quickly becomes Yuki's closest companion in the camps. They share in the daily routines and small discoveries of their confinement. She suffers from frail health but maintains a defiant spirit, often disagreeing with her grandfather's negative outlook on their situation.

Mrs. Kurihara is Emi's grandmother, who formerly ran a Japanese food shop in San Francisco with her husband. She takes an immediate liking to Yuki and brings her traditional customs to the camps. She heavily relies on folk remedies, such as earthworm tea and egg yolk essence, to treat illnesses. Her warm nature provides a comforting presence for the children.

Mr. Kurihara is Emi's grandfather, a somewhat taciturn man who struggles with the injustice of his incarceration. He expresses open frustration about being treated as an "enemy alien" and contemplates returning to Japan. Despite his rough exterior, he finds a quiet hobby in taking evening walks and collecting desert artifacts like arrowheads.

Mimi is Yuki's white schoolmate and neighbor in Berkeley. She remains a loyal friend when the political climate turns hostile. She offers Yuki gifts, including a red leather diary, to maintain their connection after the forced relocation.

Mrs. Nelson is Mimi's mother and a loyal neighbor to the Sakane family. She ensures the Sakanes experience warmth and hospitality before they are taken away. She promises to help them however she can and later drives them to the mass removal depot.

Mrs. Jamieson is an elderly white widow who lives near the Sakanes in Berkeley. She is highly sympathetic to the family's plight and outraged by Mr. Sakane's arrest. She gives Yuki a valuable pearl ring from her personal collection to remember her by.

Pepper is Yuki's pet dog in Berkeley. He represents the comfort of Yuki's childhood. Because pets are not allowed in the concentration camps, finding a new owner for him becomes a painful necessity for the Sakane family.

Jim is a friend of Ken's who arrives at the assembly center before the Sakanes. He helps the family find mattresses and a broom for their horse stall. He introduces them to the harsh realities and euphemistic language used by the camp administration.