Pinmei is a quiet young girl with a long black braid who lives in a hut on the Never-Ending Mountain. She relies heavily on her grandmother and is often described as resembling a mouse due to her extreme shyness. She possesses a deep capacity for loyalty and inherits a profound, if hesitant, gift for storytelling that becomes essential for survival.

Amah is an elderly woman renowned across the land as the Storyteller, possessing an exceptional memory for ancient myths and folktales. She works as a master embroiderer to support herself and her granddaughter. She holds deep cultural knowledge that makes her a prime target for the ambitious Tiger Emperor.

Yishan is a bold boy dressed entirely in red who lives near Pinmei on the mountain. He serves as Pinmei's best friend and confident protector. In contrast to Pinmei's quiet nature, Yishan speaks decisively and takes the lead as they set out toward the City of Bright Moonlight.

Lady Meng is a noblewoman often seen wearing shades of blue and gray. She travels to the City of Bright Moonlight in search of her missing husband. She teaches Pinmei that true bravery means facing danger despite feeling fear, providing crucial mentorship on the road.

The Tiger Emperor is a ruthless new ruler who seeks to consolidate power by conscripting men to build a Vast Wall. He rules through terror and displays a complete disregard for human life. He desires immortality above all else, an obsession that drives him to abduct Amah for her deep mythological knowledge.

King KaeJae is the burdened ruler of the City of Bright Moonlight. He is forced to comply with the Tiger Emperor's demands to protect his people. He possesses the magical Paper of Answers, which guides his decisions, but he lives in constant fear of the emperor's wrath and his ever-present spies.

The Black Tortoise of Winter is a powerful creature responsible for the harsh winter gripping the land. Forced out of the heavens and trapped on earth, his imprisonment disrupts the natural order and causes widespread suffering across the human realm.

The Sea King is a mythological ruler who presides over the underwater Crystal Palace. He summons help to address the unnatural freezing of the sea. He is knowledgeable about ancient artifacts and directs the children on their quest to resolve the environmental imbalance.

Haiyi is a servant with a scarred face resulting from her employers' past cruelty involving stingy rice. Despite the severe risks to her own safety, she offers shelter and food to the traveling group, seeking to live up to her heroic name and make a difference.

Yanna is a servant in the City of Bright Moonlight who guides Pinmei and her friends through the dangerous palace. Originally from a seaside village, she came to the city for work after the Tiger Emperor took her horse and the local men.

The stonecutter is a skilled artisan jailed for defacing a statue of the Tiger Emperor. He shares a cell with Amah, providing her with companionship and eagerly listening to her stories to pass the time in confinement.

BaiMa is Lady Meng's beautiful white horse. Loyal and swift, he serves as a crucial mode of transportation for Lady Meng, Pinmei, and Yishan during their perilous journey toward the sea.

Old Sai is an elderly villager who generously takes in Pinmei and Yishan after their mountain hut is destroyed. Despite his own family's poverty and recent military raids, he insists on sharing what little warmth they have.

Suya is Old Sai's wife, a practical woman worried about her family's survival after the emperor's soldiers took most of their resources. She softens her demeanor and shares their hidden food after hearing Pinmei's storytelling.

Sifen is the son of Old Sai and Suya. Because he is injured, he was spared from being conscripted by the Tiger Emperor's soldiers to build the Vast Wall, allowing him to stay home with his family.

Wan is Lady Meng's husband, who was sent by King KaeJae to meet the emperor in his stead. His disappearance prompts Lady Meng's perilous journey to discover his fate at the Vast Wall.

Joy to the Heart is a man dressed in silver who leans on a coral cane. He resides at the Crystal Palace at Sea Bottom and assumes a human form to make the Sea King comfortable in his domain.

Meiya is Yishan's late aunt who passed away several years ago. She raised him and provided him with clothing. She also once heard Amah's stories, connecting her to the broader history of the mountain's residents.