Johan Liebert is the titular "monster" of the story and the mystery of his past is the focus of the plot. He has been called a monster, the next Adolf Hitler and even the devil himself. Johan Liebert was shot in the head at a young age but saved from death by Dr. Tenma. Because of this, he regards Dr. Tenma almost as though he was his father. He has spent portions of his life in different places under different aliases and possesses an extraordinary level of charisma and intelligence. He uses his gifts to cruelly manipulate and corrupt others, often with no apparent end other than to cause suffering and destruction. His goal, as he stated when he was young, is to be the last one standing at the end of the world. One of the themes of Monster is how individuals are capable of transforming into monsters; Johan often acts as both a direct and indirect catalyst for this transformation.
~! During his "perfect suicide" he was shot in the head by a bystander and seemingly died, but was later saved by Kenzo Tenma !~

Dr. Kenzo Tenma is a renowned Japanese brain surgeon working at a leading hospital in Germany. One night, Dr. Tenma risks his reputation and career to save the life of a critically wounded young boy over that of the town mayor who had been planning to support the hospital financially. A string of mysterious murders begin to occur soon after the operation, and Dr. Tenma emerges as the primary suspect despite no incriminating evidence. 
 
A doctor is taught to believe that all life is equal; however, when another series of murders occur in the surgeon's vicinity, Dr. Tenma's beliefs are shaken as his actions that night are shown to have much broader consequences than he could have imagined. Leaving behind his life as a surgeon he embarks on a journey across the country to unravel the mystery of the boy he saved.

**Height:** 160cm

[Website](https://nozomusasaki.com/) | [Twitter](https://twitter.com/nozomu_s_staff)

On March 28, 2020, he announced that he had graduated from the Faculty of Law at the University of Tokyo, while working as a seiyuu.

[Website](https://www.keithsilverstein.com/) | [Twitter](https://twitter.com/SilverTalkie) | [Instagram](https://www.instagram.com/keithsilverstein/) | [Facebook](https://www.facebook.com/keithsilversteinvo) | [TikTok](https://www.tiktok.com/@keithsilversteinva)

Keith David Silverstein is an American voice actor, best known for his roles as Johan Liebert in Monster, Vector the Crocodile in the Sonic the Hedgehog video games, Robert E.O. Speedwagon in JoJo's Bizarre Adventure, Hisoka in the 2011 version of Hunter × Hunter, Oogai Mori in Bungo Stray Dogs. He is also known from several non-anime roles, including Gabriel Agreste a.k.a. Hawk Moth (Shadow Moth in later seasons) in Miraculous: Tales of Ladybug & Cat Noir, and Zhongli in Genshin Impact.

**Height:** 173 cm (5'8")
**Agency:** Himawari Theatre Group

[Profile](https://profile.himawari.net/view/1542) | [Twitter](https://twitter.com/U_Yutopan) | [Wiki (en)](https://en.wikipedia.org/wiki/Y%C5%ABto_Uemura)

Everyone faces uncertainty at some point in their lives. Even a brilliant surgeon like Kenzo Tenma is no exception. But there’s no way he could have known that his decision to stop chasing professional success and instead concentrate on his oath to save peoples’ lives would result in the birth of an abomination. The questions of good and evil now take on a terrifyingly real dimension.
 
Years later, in Germany during the tumultuous post-reunification period, middle-aged childless couples are being killed one after another. The serial killer’s identity is known. The reasons why he kills are not. Dr. Tenma sets out on a journey to find the killer’s twin sister, who may hold some clues to solving the enigma of the “Monster.”
 
(Source: Viz Media)