Pong is an observant and justice-driven boy who was born in Namwon Prison and must serve a sentence there until he turns thirteen. He possesses a strong moral compass and feels a physical burning sensation when he witnesses unfairness. Ashamed of his prison tattoo and background, he struggles with feelings of unworthiness after an encounter with the city's leader convinces him that he is destined for darkness.

Nok is the perfectionistic daughter of the Namwon Prison warden. She believes implicitly in law and order, trusting that strict rules guarantee fairness. Driven by a need to prove her worth to her parents amid swirling high-society gossip, she uses her impressive spire-fighting martial arts skills to track down rule-breakers and enforce the law.

Somkit is Pong's best friend and a fellow resident of Namwon Prison. Physically smaller than the other children and prone to coughing fits, he relies on Pong for protection but possesses a sharp, mechanical mind. He tends to avoid conflict, preferring to stay quiet rather than invite punishment from the guards.

The Governor is the authoritarian ruler of Chattana, revered by the upper classes as a savior who restored light to the city after the Great Fire. He maintains absolute control over the population by generating the magical light orbs that power all modern conveniences. He enforces rigid laws and dictates that his light only shines on those he deems worthy.

Father Cham is the elderly, serene head monk at Wat Singh in the village of Tanaburi. He leads his community with deep compassion and treats everyone with equal respect, regardless of their social standing. He possesses a unique ability to grant small blessings that come true, tying them into woven cords he gifts to visitors.

Ampai is the fiercely optimistic leader of an underground resistance network operating out of the Mud House in Chattana. She provides refuge for the city's impoverished citizens and organizes peaceful protests against the Governor's oppressive pricing of light orbs. She constantly looks for ways to repair broken systems and inspire hope in desperate people.

Warden Sivapan is the chief administrator of Namwon Prison and the patriarch of the Sivapan family. He occasionally displays leniency toward the prisoners, which clashes with the strict regulations set by the Governor. He tries to shield his family from high-society gossip by relocating them to the rural village of Tanaburi.

Ploy is one of Nok's younger twin sisters. Raised in a wealthy, privileged household, she firmly believes her family's teachings about the inherent criminality of the children born in the reform center.

Tip is Nok's younger twin sister. Like Ploy, she views the inmates of Namwon with disdain and openly repeats mantras about how children of criminals are destined to become criminals themselves.

Officer Manit is a police officer assigned to the East Side of Chattana. Unlike the strict and punitive guards at Namwon Prison, he shows genuine kindness toward the street children, occasionally offering them spare change and warnings about local dangers.

Yord is one of Ampai's personal bodyguards at the Mud House. He helps enforce the rules of the tenement and runs side schemes selling faded light orbs on the black market to naive customers.

Yai serves as a bodyguard for Ampai at the Mud House. Along with his partner, he monitors the tenement building and engages in illicit trades involving faulty light orbs at the local markets.