Frighteningly addictive.
"Monster" is a deep and meaningful psychological thriller one should at least watch/read once in his life.

In this one, Urasawa allows us to explore the most classic theme in all medias: the duality of good and evil. The darkness and light that co-exist in each human being.

As we follow the journey of Dr Tenma, mistakingly convincted for murder, and devoured by his own guilt for saving a kid ,Johan, who turned into the most deranged and manipulative psychopath, we get to know a plethora of characters along the way: each one getting a different backstory, and serving a different purpose, giving a most humane et realistic feeling to the story.

As we delve deeply in the psyche and the memories of the characters, through one sentence "Look at me, the monster inside of me is growing bigger" we get to ask ourselves : who is the real monster ? Is it the loneliness and darkness that devours the heart of the abandoned kids ? Is it the one who choose to brainwash them ? Is it the mother who chooses to sacrifice one of her children ? Is it the one who can't feel compassion but only emptiness ?

And what makes a human 'exist' ? Is it his ability to feel ? Is it his memories ? Or the name he was given that makes him part of the world and be remembered?
In the end, Urasawa lets his readers decide what is the good answer: none and all of these.

To sum it up, except a few minor "flaws", quickly erased by the extraordinarily developed characters and the complex themes explored here, calling "Monster" a masterpiece is an understatement.