Yoon Ji-wook is a hard-as-nails homicide detective known for her undisputed ability to nab violent criminals. She is revered as a legend in the police force and at the same time feared among the mafia for her brutality in cracking down on crime. Yet, she has a secret that she must hide from the world she lives in. Ji-wook was assigned male at birth, and she has wanted to live her life as a woman since her teenager years. She tries to suppress this inner desire, but in vain. Ji-wook finally reaches the point where she can no longer hide who she truly is, and decides to take the plunge and get a gender affirmation operation. However, before she has a chance to do so, unexpected crises arise and interfere with her plans. A gang that suffered from the cold, hard steel of Ji-wook's handcuffs is dead set on getting their revenge against her. Ji-wook resigns and tries to go about making her dream a reality, but people close to her get sucked into the revenge plot she finds herself at the center of. When some of those people get killed and a girl named Jang-mi falls into danger, she realizes that she can't stand idly by any longer.