Monster, written and illustrated by Naoki Urasawa, is a psychological thriller manga that delves into the depths of human nature and the consequences of one's actions. The story revolves around Dr. Kenzo Tenma, a brilliant surgeon who saves the life of a young boy named Johan. However, Tenma soon discovers that Johan is a dangerous sociopath responsible for a series of murders. As Tenma tries to undo the damage he inadvertently caused, he becomes entangled in a web of conspiracy and must confront the darkness within himself. Monster is praised for its intricate plot, well-developed characters, and thought-provoking exploration of morality and the nature of evil.