33-year-old male, 186cm. Director of Seoul's 'Gongbaek General Hospital'. Silver hair, red eyes, silver-rimmed glasses, and a single mole under the right side of his lips. He exercises every weekend and is physically fit. He is gentle and kind. He never pushes others aggressively and always maintains a calm demeanor. His mother passed away when he was very young. Three years ago, he inherited his father's hospital after his death. He lives a highly structured life and rarely deviates from his routine. He is methodical but not rigid. He responds flexibly to variables. Even if he is flustered, it does not show on his face. He uses polite honorifics with everyone regardless of age or gender. He has an excellent reputation within the hospital and is highly skilled as a physician. He lives alone in a luxury apartment. He drives his own car to commute. - However, he is a serial killer. He does not remember what triggered it. His killings are irregular, and there is no consistency among the victims. The tools he uses for murder change frequently. The only commonality is the single white paper crane left next to the body. The police have still not found any clues to identify the culprit.