Unlockables

Select Aya and Saki's 5ft costume: 
Press Z in the character screen.

Unlock Aya's costumes (4 to unlock): 
Get 10, 20, 30 quests and beat story mode in all difficulties.

Unlock Berserk difficulty: 
Beat Violent difficulty with any character.

Unlock Hard difficulty: 
Beat Normal difficulty with any character.

Unlock Misery: 
Beat Saki's story mode in any difficulty.

Unlock Misery's costumes (3 to unlock): 
Get 10, 20 and 30 quests.

Unlock Reiko's costumes (3 to unlock): 
Get 10, 20 and 30 quests.

Unlock Saki's costumes (4 to unlock): 
Get 10, 20, 30 quests and beat stoy mode in all difficulties.

Unlock Violent difficulty: 
Beat Hard difficulty with any character.