Character thoughts.
"In all, 'Monster' examines human nature and the manifestations of 'Self' and what humans are capable of given the right conditions and 'education'. Images of duality, weighing mostly on the side of the 'Dark' constantly remind us of how weak and vulnerable human beings are when faced with fear, hate, uncertainty, etc. How easily we yeild to negative emotions and pessimistic perspectives, feeding our ego with darkness until we are consumed from the inside by the hungry, nameless 'Monster'. Johan perhaps represents an ultimate evil that exists in every person, young and old, while close at hand Tenma the brightest image of all that is good and pure. And yet, both Johan and Tenma are mere reflections of each other and neither can exist without the other. Both can be interpreted as playing the role of Christ, depending on your viewpoint. Though in the end it is Johan who is doomed to be the tragic hero, the fallen angel burdened with the evils of mankind. The multitude of characters are scattered along the spectrum between these two, disorientated like a line of ants sent running in all directions by a human finger, a single breath. The messages carried by the horrific picture books and ultimately by the man who created them and gave rise to the story still apply in our world. It challenges those elusive notions of 'belief' and 'conscience'. Is seeing believing? Can we trust our minds? The emphasis placed on 'Self' cannot be more profound. That is why I find this story so captivating, so confronting and so damned good."
Hm... I guess the bold kind of explains why Tenma is the only person that Johan can't kill, and why Tenma never ends up killing Johan, too. (Although Johan will mess with the poor doctor's mind in an instant. XD;; ) Also can be interpreted in another way, but let's not get into that. *SWATS AWAY FANGIRLISM*
But yeah.