Mouse - Characters & Cast

Initially driven by a predatory bloodlust and the desire to hide his true self; after the surgery, his motivation shifts to atonement and destroying the monsters (including his own biological father) who created the cycle of violence.

Initially presented as the ultimate 'good citizen' and kind cop, his arc takes a shocking turn when it is revealed he is the actual serial killer. After a brain transplant from the innocent Sung Yo-han, he develops emotions and guilt, eventually turning himself in and seeking redemption through death.

Revenge against the Head Hunter and his perceived successor. His motivation evolves into uncovering the truth behind the OZ conspiracy and finding peace for his brother's soul.

A detective whose life was shattered by the Head Hunter. He starts as a reckless, alcoholic officer driven by hate, but through the series, he learns the painful truth about his 'partner' Ba-reum and the innocent Yo-han, leading him to a more complex understanding of justice and forgiveness.

Protection of her grandmother and personal safety. Her motivation eventually shifts to survival and moving past the betrayal of the person she trusted most.

A high school student who survived a sexual assault as a child. She grows from a traumatized, fearful girl into a fierce fighter who learns martial arts to protect herself. Her relationship with Ba-reum is her source of light until the truth destroys her world.

To prove he is not a monster like his supposed father and to stop the real killer, Jung Ba-reum, to protect his mother and unborn child.

A genius doctor stigmatized as the 'Head Hunter's son.' He remains silent and aloof, leading the world to believe he is a killer. In reality, he was an innocent man trying to stop the real murderer. He dies a tragic death, and his brain is used to 'save' the actual killer.