Pierrot is a young boy of French and German descent who experiences profound loss early in life. Small for his age and often bullied, he harbors deep insecurities and a strong desire to belong. When he moves to his aunt's home in Austria, he adopts the Germanized name Pieter and struggles to balance his gentle upbringing with the intimidating environment of his new home.

Anshel is Pierrot’s deaf, Jewish neighbor and closest childhood friend. He is an exceptionally bright boy with a passion for reading and writing stories. Despite the rising anti-Semitism in Europe, Anshel remains steadfast in his values, providing a grounding moral presence in Pierrot’s early life.

Beatrix is Wilhelm’s sister and the head housekeeper at Berghof, a secluded mountain mansion. She is a pragmatic, protective woman who takes Pierrot under her wing when he is orphaned. She urges her nephew to shed his French identity and sever ties with his past to keep him safe from the dangerous political environment of her workplace.

Known as the Führer, Hitler is the powerful master of the Berghof mountain retreat. He takes an unexpected interest in Pierrot, bonding with him over a shared love of dogs and their respective backgrounds. He uses his immense authority to mold Pierrot's worldview, introducing the young boy to Nazi ideology and granting him a sense of importance he previously lacked.

Emma is the cook at the Berghof estate. She is a practical and observant member of the house staff who frequently interacts with Pierrot. Emma serves as a steady, moral presence in the household, quietly adhering to her own sense of justice despite the intimidating atmosphere of the mountain retreat.

Ernst is the official chauffeur at Berghof. He presents a confident and capable demeanor, catching Pierrot's admiration with his crisp uniform. Alongside Beatrix, he tries to counsel Pierrot on how to safely survive life at the estate, warning the boy about the dangers of drawing unwanted attention.

Herta is a maid at the Berghof estate who strictly enforces the household rules. Initially brusque and impatient with Pierrot, she treats him like a small child and insists he abandon his old French clothing. Beneath her strict exterior, she understands the realities of their environment and pushes Pierrot to adapt.

Wilhelm is Pierrot’s German father, a veteran of the First World War who works as a waiter. Deeply scarred by his combat experiences, he turns to heavy drinking to cope with his trauma, making him volatile and prone to anger. Despite his flaws, he instills a sense of German pride in his son.

Émilie is Pierrot’s devoted French mother who works as a waitress to support her son. She strives to provide a loving and stable home despite the emotional and financial strain caused by her husband's wartime trauma.

Simone is one of the two sisters running the Orléans orphanage. She is straightforward, realistic, and slightly aloof compared to her sister. She tries to instill a message of tolerance in the children and provides Pierrot with a beloved book before he departs for Austria.

Adèle helps run the orphanage in Orléans with a sunny, optimistic, and nurturing disposition. She does her best to comfort Pierrot during his difficult transition and packs him food for his train journey to Austria.

Hugo is a resident at the Orléans orphanage and the nephew of the Durand sisters. He targets Pierrot with physical bullying, acting out his own frustrations and carrying the weight of his family's traumatic past.

Josette is a young girl at the Orléans orphanage who has been adopted and returned multiple times for being disruptive. She quickly befriends Pierrot and fiercely defends him against other bullies.

Katarina is a confident schoolmate of Pierrot's in the village near Berghof. She initially befriends him and defends him against classmates who mock his French accent, though she grows increasingly critical of his political beliefs and arrogance as he becomes entrenched in his new lifestyle.

Mrs. Bronstein is Anshel's widowed mother. She is a kind and generous woman who attempts to take Pierrot into her Jewish household permanently, but is ultimately forced by financial constraints to send him to an orphanage.

Eva is the partner of the master of Berghof. She treats Pierrot affectionately, viewing him as a cute and harmless child, which occasionally irritates his growing desire to be taken seriously as an adult.

Kotler is an aggressive teenage member of the Hitlerjugend who shares a train compartment with Pierrot. He bullies the younger boy, stealing his food and mocking his French heritage.

The abdicated King Edward VIII of England visits the mountain retreat to discuss a potential political alliance. He is a high-profile guest who brings a flurry of anxious preparation to the estate's staff.

Wallis, the Duchess of Windsor, attends diplomatic meetings with her husband. She patronizes Pierrot during her visit, speaking to him as if he were merely an entertaining toy, which bruises his fragile ego.

Daniel is a dockworker who befriends Pierrot in Belgium years after the war. He wears long sleeves to conceal a deeply traumatic past, carrying the heavy burden of losing his entire family in the conflict.