Diary of a Murderer opens with a gripping first-person perspective that pulls readers immediately into the mind of its complex narrator, an aged serial killer grappling with Alzheimer's. From the start, this unsettling and introspective journey is marked by a darkly comedic tone and a haunting exploration of memory, identity, and moral decay. The narrator's wit and detached yet deeply personal storytelling add unexpected depth and, at times, disarming humor to a thriller that otherwise grapples with heavy themes.

The main story leaves readers questioning both reality and the narrator's recollections—an unreliable narration that captivates, even as his memory deteriorates. As we’re taken through his convoluted sense of morality, the lines blur between his past and present crimes, leaving readers to unravel whether his intended last murder is more a product of his fragile memory or a chilling reflection of his truest self.

The additional short stories in the collection delve into themes of love, loss, and obsession, each with unique characters facing morally complex situations. The Origin of Life, the second story, introduces Seokjin and Ina, whose toxic relationship unfolds against a background of financial and emotional despair, yet the tale is undercut by questions about its thematic relevance to the collection. While The Missing Child faltered somewhat in capturing your interest, The Writer takes a shockingly surreal turn, pushing the boundaries of Kim’s exploration into obsession and identity, making it the most unforgettable—if bizarre—entry in the collection.

Ultimately, Diary of a Murderer is a thought-provoking and bold anthology that captures the intricacies of the human psyche under extreme conditions. Young-ha Kim skillfully balances philosophical reflection with narrative tension, leaving an impression both unsettling and profound.