Adam is a non-religious Polish Jew and former foreign language teacher who is relocated to the Warsaw ghetto. Grieving his late Catholic wife, Kasia, he maintains a surprisingly optimistic outlook and tries to protect his young students by teaching them happy poetry. Because of his background in languages and literature, he gets recruited for a secret archival project documenting ghetto life.

Sala is a mother of two boys who shares a crowded ghetto apartment with her husband Emil, Adam, and the Lescovec family. Raised in a sheltered religious home, she desires freedom and possesses a deep love for her children. She finds comfort in conversing with Adam about her past life and her dreams.

Szifra is a striking 15-year-old student of Adam's whose blond hair and blue eyes allow her to pass as ethnic German. Following her father's suicide and her mother's declining health, she assumes the heavy burden of providing for her two younger brothers. She relies on extreme pragmatism, making dangerous compromises with guards to secure resources for her family.

Henryk is Adam's wealthy, well-connected Polish Catholic father-in-law. He genuinely loved his daughter Kasia and extends a patronizing affection toward Adam. He behaves opportunistically, using his supposed benevolence to manipulate Adam into giving up his apartment and valuables.

A historian who organizes the Oneg Shabbat Archive within the ghetto. He believes strongly in recording a comprehensive, objective account of Jewish life under oppression. He pushes his contributors to gather stories from all walks of life, refusing to shy away from uncomfortable truths.

Sala's husband and a Lithuanian former businessman who used to sell sewing machines. In the ghetto, he serves as a counselor to the Judenrat (Jewish council) and attempts to maintain his dignity and professional appearance despite their harsh living conditions.

Adam's late wife, a Polish Catholic woman who died from a brain injury following a fall prior to the war. Her memory grounds Adam, while her remaining wedding jewelry serves as his only potential currency for survival.

An 11-year-old boy who shares the apartment with Adam and the Wiskoffs. A former school soccer player, he copes with the ghetto's restrictions by carving wooden figurines with a Swiss Army knife and participating in the dangerous underground smuggling network.

Filip and Jerzy's mother, and one of Adam's housemates. The daughter of a former fishmonger, she carries the grief of experiencing anti-Semitism from people she once considered close family friends prior to the invasion.

Filip's older brother. He attempts to maintain a sense of normalcy in the ghetto by pursuing a romance with a girl from a neighboring street, eventually proposing marriage.

Sala and Emil's older son. Like many children in the ghetto, he endures extreme deprivation and occasionally secures extra food for the household through barter and smuggling.

Sala and Emil's younger son. He finds brief moments of childhood joy by participating in makeshift entertainment like courtyard dog races with other children.

Szifra's younger brother. Following his parents' tragedies, he becomes entirely dependent on Szifra's dangerous efforts to secure resources and papers for their survival, occasionally asking Adam to teach him German.

Szifra's youngest brother, who retains very few memories of life before the ghetto. He relies completely on his older sister for food and survival.

One of Adam's young students in the ghetto. He attends lessons with his sister Charlotte and frequently squabbles with the other children about their bleak circumstances.

An 11-year-old student who lives in the ghetto. She shares her family's complex history with Adam for the archive, expressing a desire for a traditional family life rather than mimicking her rebellious older sister.

A Polish guard who acts as a smuggler and intermediary. He profits off the desperate Jewish residents by selling smuggled goods at highly inflated prices and delivering messages from the outside.

A cynical fellow member of the Oneg Shabbat project. He views the archival work as a futile exercise, believing that the horrific circumstances of the ghetto have exposed the innate selfishness of its residents rather than their nobility.

Szifra's late father, who owned a clothing factory before the war. His inability to cope with the loss of his business and status led to his suicide, leaving his family vulnerable.

Emil's late mother who moved in with Emil and Sala after her husband died. She essentially took over running their household and preserved a copy of their family's 300-year-old lineage before being tragically killed by a guard during the ghetto relocation.

Kasia's mother and Henryk's wife. She holds strong prejudices and completely disowned Kasia for choosing to marry a Jewish man, famously cursing Adam at the wedding.