Monster, written and illustrated by Naoki Urasawa, is a suspenseful seinen manga series that follows the story of Dr. Kenzo Tenma, a brilliant surgeon who becomes entangled in a web of conspiracy and murder after saving the life of a young boy who turns out to be a psychopathic killer. As Tenma tries to unravel the truth behind the boy's actions, he finds himself pursued by a relentless detective. With its intricate storytelling, complex characters, and exploration of moral ambiguity, Monster is widely regarded as a masterpiece of seinen manga.