Diario di un killer sentimentale is a contemporary fiction novella by Luis Sepúlveda that blends noir elements with introspective narrative. The story follows a professional hitman reflecting on his final assignment while dealing with the emotional aftermath of a failed romantic relationship. Written in a sharp, minimalist style, the diary format reveals contradictions between the killer’s detached profession and his internal vulnerability. Sepúlveda uses the crime genre to explore loneliness, loss, and identity, turning the figure of the killer into a vehicle for existential questioning. The book is concise yet psychologically layered.