Tantei wa Mou, Shindeiru.

The Detective Is Already Dead follows Kimihiko Kimizuka, a boy who seems to attract trouble wherever he goes, and Siesta, the silver-haired detective who pulls him from one impossible case into the next. Their first meeting takes place on a hijacked flight, and what begins as a chance encounter soon becomes a tense partnership defined by Siesta’s sharp deductions and Kimizuka’s instinct for surviving the chaos around them. Together, they are drawn through hijackings, conspiracies, and mysteries that never stay confined to a single incident. As their cases widen, Kimizuka is pulled deeper into a shadowy network of hidden agendas, dangerous enemies, and unanswered questions tied to Siesta’s work. Her influence leaves a lasting mark on everyone around her, and even after their partnership changes, the aftermath of what she set in motion continues to shape his path. The story gradually expands beyond their first encounters as new allies and rivals enter the picture, including Nagisa Natsunagi, forcing Kimizuka to keep moving forward while confronting the legacy Siesta leaves behind.