Tomikazu is a thirteen-year-old eighth grader who plays catcher for the Rats, a local grassroots baseball team. Born in America to Japanese immigrants, he balances the traditional expectations of his family with the American culture surrounding him in Honolulu. He takes pride in his heritage but longs to fit in with his peers, often hiding his family's financial struggles from his friends.

Taro is a hardworking Japanese fisherman who spends days at sea to provide for his family. He maintains a quiet, accepting demeanor and readily welcomes Tomikazu's white friends into their home. At home, he finds peace in caring for his flock of nearly forty racing pigeons.

Mama Nakaji is a resilient woman who traveled to Hawaii from Japan as a picture bride at age sixteen. She works tirelessly as a maid for the Wilson family to support her household. Her fierce protectiveness serves as the emotional backbone of the Nakaji family.

Joji is Tomikazu's traditional Japanese grandfather who lives with the family. A stroke survivor and former fisherman, he now tends to the household chickens. He proudly displays his Japanese heritage, often ignoring the social tensions his actions create in their neighborhood.

Billy is a thirteen-year-old white mainlander who pitches for the Rats baseball team. He lives next door to the Nakajis in a spacious house. Open-minded and generous, he gradually learns to appreciate the cultural differences between his upbringing and Tomikazu's traditional home life.

Keet is the sixteen-year-old son of the Nakaji family's landlord. Once friends with Tomikazu, he is now a malicious bully who torments the Nakajis and openly resents their Japanese heritage. He frequently spies on the family and looks for opportunities to cause trouble.

Kimi is Tomikazu's sweet five-year-old sister. She is a shy girl who often hides behind her mother's skirts. She finds joy in playing with the family's animals and offers a source of innocence for the family.

Mose is a Portuguese American eighth grader who plays center field for the Rats. He is tough, hardworking, and fiercely loyal to his friends on the team, readily defending them against rival gangs.

Rico is the first baseman for the Rats. He sports a visible scar on his chin from a past conflict involving soldiers. Like his brother, he offers steadfast support to Tomikazu and refuses to back down from physical intimidation.

Charlie is an older Indigenous Hawaiian man who works as a gardener for the Davis family. He is a wise, culturally respectful friend to the Nakajis. He allows the local boys to listen to baseball games on his radio and provides level-headed advice during crises.

Sanji is a hardworking nineteen-year-old assistant who helps Taro Nakaji on his fishing boat. He works multiple jobs to support his wife and young daughter. Despite initial superstitions, he forms a genuine bond with Billy Davis during a long fishing excursion.

Mr. Wilson is Keet's father and the landlord to the Nakaji family. He strongly objects to any displays of Japanese culture on his property and demands strict adherence to his rules.

Mrs. Wilson is Keet's mother and the primary employer of Mama Nakaji. She relies on her employee to clean the large Wilson home.

Jake is Billy's older brother. He sometimes associates with Keet Wilson but demonstrates more fairness, eventually distancing himself from Keet's extreme bullying.

Mr. Davis is Billy's father, who works for the Matson Navigation Company. He provides a comfortable upper-class home for his family and occasionally advocates for his neighbors.

Mrs. Davis is Billy's mother, who works as a nurse. She helps maintain a comfortable and secure home for her family.

Reiko is Sanji's wife. She lives in a small, run-down apartment with her young daughter and mother-in-law, managing her household under strict financial constraints.

Mari is Sanji and Reiko's enthusiastic three-year-old daughter. Her joyful reactions mirror her father's good nature.

Mr. Ramos is a former lawyer turned science teacher at Tomikazu's school. He advocates for guiding boys early to prevent them from getting into trouble, drawing from personal family history.

Ichiro is the respected leader of the Kaka'ako Boys, a grassroots Japanese American baseball team that plays against the Rats. He commands authority among the local teenagers.

Gayle is a massive, hard-throwing pitcher for the Kaka'ako Boys who earns the nickname "The Butcher." Despite his intimidating size and power, he possesses a surprisingly soft, wispy voice.

Tough Boy is a batter for the Rats who bravely steps up to the plate against opposing pitchers, refusing to back down from intimidation.

Lucky is the Nakaji family's loyal dog. She gives birth to a litter of puppies and fiercely protects them from local predators like mongooses.

Red is the smallest puppy from Lucky's litter. Billy Davis chooses him, establishing a small bond between the two households.