Monster

Kenzou Tenma is a talented Japanese brain surgeon working in Germany who chooses to save the life of a young boy instead of a prominent politician, a decision that ruins his career and reputation. That boy turns out to be Johan Liebert, a charming yet deeply dangerous individual whose later actions set off a chain of murders and manipulations across Europe. Years on, Tenma becomes obsessed with stopping Johan and trying to make amends, tracing a trail of ruined lives, shadowy institutions, and buried identities. Nina Verdona, former allies, and survivors cross paths with Tenma as the story peels back past experiments and personal histories that created the monster at the center.

Released in 2004, Monster adapts Naoki Urasawa's acclaimed manga, with Tatsuhiko Urahata handling series scripts, keeping the original story's intricate plotting and psychological focus for television.

While it didn't sweep mainstream international awards, Monster has strong critical esteem and a devoted fanbase. It regularly surfaces in critics' and audience lists of top anime, noted for treating adult themes and crime drama with uncommon seriousness in animated form.

Johan Liebert is often mentioned as one of anime's most unsettling antagonists, and the series helped push psychological thrillers toward more realistic, morally ambiguous storytelling. Its influence shows up in discussions, essays, and creator acknowledgments, and it broadened what many viewers expect from long-form animated narratives.

Critics praised Monster for patient pacing, complex characters, and moral ambiguity, reflected in its high audience rating. Major themes include guilt, professional responsibility, identity, and the societal consequences of trauma and manipulation. The show asks uncomfortable questions about culpability and the nature of evil, making it best suited for viewers who prefer slow-building, cerebral crime drama with emotional weight.