Moon Dong-eun is a quiet, calculating, and fiercely resilient woman who survives years of horrific school violence before dedicating nearly two decades to a meticulously planned revenge. Patient, emotionally restrained, and highly intelligent, she carefully dismantles the lives of those who destroyed hers. Despite her cold exterior, she longs for justice rather than forgiveness, finding an unwavering ally and eventual love in plastic surgeon Joo Yeo-jeong, who stands beside her throughout her journey. With short black hair, dark brown eyes, and a minimalist wardrobe of trench coats and dark turtlenecks, Dong-eun carries the scars of her past with unwavering determination.

Joo Yeo-jeong is a brilliant plastic surgeon whose warm, gentle nature conceals deep psychological scars from his father's murder. Intelligent, compassionate, and unwaveringly loyal, he becomes Moon Dong-eun's devoted ally, offering to be her "executioner" as she carries out her years-long revenge. Though a healer by profession, he embraces vengeance to protect the woman he loves while confronting his own painful past. With dark brown hair, dark brown eyes, and a clean, minimalist style, Yeo-jeong balances kindness with a quiet darkness glad to kill anyone she asked.

Kang Hyeon-nam is a resilient housekeeper and domestic abuse survivor who becomes Moon Dong-eun's loyal ally, undercover investigator, and trusted assistant in exchange for protecting her daughter. Resourceful, sharp, and fiercely maternal, she quickly masters surveillance and tracking to aid Dong-eun's revenge. Despite years of hardship, Hyeon-nam remains optimistic, courageous, and determined to build a better future. She has black hair and dark brown eyes.

Park Yeon-jin is a wealthy weathercaster and the ruthless ringleader of the group that brutally bullied Moon Dong-eun throughout high school, becoming the primary target of Dong-eun's years-long revenge. Cruel, arrogant, narcissistic, and obsessed with control, Yeon-jin hides behind wealth and status to protect her perfect image. Though fiercely protective of her daughter, she treats those around her as tools to maintain her power. With long black hair, dark brown eyes, and an elegant, luxury-inspired style, Yeon-jin believes she is untouchable—until her past catches up with her.

Jeon Jae-joon is a wealthy luxury boutique and golf resort owner who was one of the main bullies responsible for tormenting Moon Dong-eun throughout high school. Arrogant, violent, and deeply entitled, he uses his wealth and power to intimidate others. He maintains a long-running secret affair with Park Yeon-jin while later becoming obsessively possessive of their biological daughter. Insecure about his colorblindness and quick to anger, Jae-joon believes he can always get what he wants. With slick black hair, dark brown eyes, and a sharp luxury style, he exudes confidence and privilege.

Ha Do-yeong is the wealthy CEO of a major construction company, Park Yeon-jin's husband, and the devoted father to his daughter. Calm, stoic, and highly strategic, he approaches life like a game of Go, valuing order, logic, and control above all else. His seemingly perfect marriage crumbles as Yeon-jin's violent past and affair with Jeon Jae-joon come to light, leading him to quietly dismantle the life they built together. Though fascinated by Moon Dong-eun's calculated mind, his greatest priority remains protecting his daughter. With black hair, dark brown eyes, and an impeccable quiet-luxury style, Do-yeong carries himself with effortless sophistication.

Lee Sa-ra is a celebrated abstract painter, the daughter of a prominent pastor, and one of the wealthy bullies who brutally tormented Moon Dong-eun throughout high school. Self-absorbed, erratic, and deeply hypocritical, she hides a severe drug addiction behind a polished religious image. Entitled and dismissive, Sa-ra's carefully crafted life begins to unravel as Dong-eun exposes her secrets. With dark brown eyes, hair that later changes from black to blonde, and a bohemian, artistic style, she embodies privilege masking chaos.

Choi Hye-jeong is a flight attendant and one of the former bullies who tormented Moon Dong-eun throughout high school. Coming from a modest background, she is desperate to climb the social ladder, using wealthy men and romantic relationships to gain status, luxury, and security. Vain, insecure, and obsessed with appearances, Hye-jeong manipulates others for personal gain, readily betraying even her closest friends when it benefits her. With dark brown eyes, black hair, and a flashy, glamorous style, she values status above all else.

Son Myeong-o is a lower-class errand runner and one of the former bullies who helped torment Moon Dong-eun throughout high school. Arrogant, greedy, and opportunistic, he serves the wealthy clique—especially Jeon Jae-jun—while secretly resenting his place beneath them. Obsessed with money and status, Myeong-o is quick to betray anyone for the right price. With shoulder-length black hair, dark brown eyes, a gritty streetwear style, and his signature "mori" neck tattoo, he masks cowardice with violence and bravado.