The world is nothing but a series of metamorphoses, from changing who you are internally to be a better person to the actual act of growing from a baby to an adult to the elderly. In the world of Osamu Tezuka, transformations show the darkness of humanity. One machine turns humanity's cast-offs into easily-hunted prey. A dancing farmer is turned into a put-upon vagrant only supported by his cat. A giant oaf turns out to be the sweetest and effeminate best friend you could hope for.

(Source: DMG)