Extra Characters 
     Beat the game with the characters to unlock more.

Unlockable:             How to Unlock:
Cornelius               Beat the Game with Gwendolyn
Mercedes                Beat the Game with Cornelius
Oswald                  Beat the Game with Mercedes
Velvet                  Beat the Game with Oswald

Heroic Difficulty - A difficulty where your HP never increases
     Obtain all text, recipes and alchemy

End Book - A final book including all characters
     Beat all 5 books, Gwendolyn, Cornelius, Mercedes, Oswald and Velvet