The story begins in 1986. Kenzou Tenma is an excellent neurosurgeon who practices his profession at the prestigious German hospital Memorial Eisler. Tenma is the best surgeon in the hospital and that is why he is entrusted with the operations of the most powerful citizens and he has also become engaged to the daughter of the hospital director.
All this means that he will have a successful future full of luxuries ahead of him, however everything changes with the arrival of twins brother and sister to the hospital: Johan Libheart, a boy with a bullet embedded in his skull and his sister Anna, in a state of shock; after all, the children’s adoptive parents were found dead in their home.
Tenma is about to start Johan’s operation, but the mayor of the city arrives in a state of emergency with a thrombosis, and Tenma’s superiors order him to abandon the minor and operate the mayor, however, he decides to act on his own and treat his first pacient and then stays with Johan.
The mayor, being treated by another doctor not as experienced as Tenma, passes away, but Johan survives thanks to Tenma. All this incident will seriously harm Tenma: he is dismissed from his position as director of the neurosurgery area, his fiancée breaks up with him, he loses the support of the hospital director, he is not allowed to see Johan and his reputation falls down completely. Days later, the doctors and the director who benefited from the fall of Tenma die one by one, and Tenma, being the most benefited by the murders, is the main suspect. The twins disappear and no one finds a trace of them.
After nine years, Tenma has a meeting with Johan and he confesses that the murders that occurred in the hospital years ago were his doing and that he did them as a token of his gratitude for saving his life. Now, Tenma discovers that he is the author of several unsolved murders, mostly of middle-aged couples.
After their encounter, Tenma decides to give up medicine to stop the “Monster” and prove his innocence. Tenma doesn’t go alone on his way to stop Johan, he encounters allies, including Nina Förtner (Anna), Johan’s twin sister, who thinks the only way to stop her brother is killing him.
If that was not enough, the police is after Tenma and the person in charge of the case is Inspector Heinrich Lunge, who has followed Tenma’s case for years because of the hospital incident, and stands out for being extremely cold and calculating, having solved all his cases thus far, except the one mentioned above.
(🢒M⊙NS†ER🢐)