Platinum Games has released a developer diary featuring Hideki Kamiya and Yusuke Hashimoto discussing the backstory for Bayonetta.
Apparently, the witch has lost her memory one the battle withe angels begins, but as the game progresses she regains it and it is up to the player to find the mysteries surrounding her past.
Also mentioned was the creative license the designers were given with enemies, weapons, and the ability to customize Bayonetta.
It is never mentioned why her head looks smaller compared to the rest of her body, but that is not what matters. What matters is that the game looks badass, and will hopefully play that way as well.
Video is past the break, game’s out early 2010.