Lan is a human child acting as the narrator, functioning as an "everyperson" with unspecified gender or race. Trying desperately to help their family fit in on the alien planet Choom, Lan maintains a cheerful facade, comparing their role to that of a golden retriever. They strongly believe in the power of comedy to bridge cultural divides, taking significant social risks to make the hostile Zhuri laugh.

Ila is Lan's older sister and a former semi-famous singer who made it to the final rounds of a major competition right before Earth's evacuation. The loss of her home and her passion leaves her deeply withdrawn. Her musical talent becomes the primary reason the Zhuri government selects their family as the test case for human settlement, placing immense pressure on her to perform.

Marf is an Ororo, an alien species resembling a giant white-and-blue marshmallow. Highly intelligent and mechanically gifted, she builds robots and secretly trades in illegal entertainment media. She challenges the social norms of Choom by befriending species outside her own and rejecting the strict anti-emotion laws enforced by the ruling government.

Amora is Lan and Ila's mother and a governing official for the human refugees on Mars. She excels in diplomacy, constantly searching for careful, non-confrontational ways to advocate for her people's survival. She bears the heavy burden of keeping her family safe while trying to reason with a hostile alien government that wants to reject human settlement entirely.

Kalil is Lan and Ila's father, working as a scientist for the human refugees. On Mars, his attempt to create a food substitute resulted in a disgusting product that sparked riots, an event that still causes him anxiety. He tries to remain positive and supportive as he starts a new, difficult job under intense alien scrutiny on Choom.

Ezger is a Krik, a fuzzy gray alien resembling a werewolf. Despite the Krik's historical reputation for eating Ororos, Ezger maintains a polite friendship with Marf. He possesses a gentle demeanor that contrasts sharply with the aggressive stereotypes surrounding his species, and he quickly takes an interest in human culture.

Naya is Lan's best friend and creative partner in producing comedy videos back on Mars. She remains on the refugee ship orbiting Choom while Lan's family goes down to the surface, frequently texting Lan for updates. Her messages reflect the mounting fear and desperation of the humans trapped in orbit without a home.

Leeni is a Zhuri working for the Immigration Division of Choom's government. Initially terrified of the humans, he frequently emits a sour-milk smell indicating fear. As he spends more time managing Lan's family's settlement, he observes the humans closely and begins to question the anti-human propaganda broadcast by his superiors.

Iruu is a young Zhuri student assigned to help guide Lan and Ila at their new school. Unlike many adults in his society, he shows curiosity about human culture and a willingness to experience emotions. He harbors a secret appreciation for Lan's physical comedy, representing a younger generation open to change.

Hooree is a young Zhuri student who strictly adheres to her government's anti-emotion laws and anti-human messaging. She frequently scolds others for breaking the rules and remains highly suspicious of Lan's family. Her behavior serves as a direct reflection of Choom's deeply prejudiced society and the effectiveness of state media.

Jens is a friend of Lan and Naya from their time living in the Mars colony. Overwhelmed by the terrifying prospect of moving to an alien world, he ignores scientific evidence about Earth's toxicity. He chooses to return to his ruined home planet with his family rather than risk the long, uncertain journey to Choom.