Onimusha 3: Demon Siege 
PS2   

Easy difficulty:

 Lose twice on Normal.  
 Hard difficulty:

 Beat the game on Normal.
 Critical (Issen) mode:

 Beat the game on Hard. 
 Oni Hard mode:

 Beat the game on Critical (Issen) mode. 
Genma Puzzle  game:

 Solve all the puzzles in the game.  
 Secret Training mode game:

   Beat normal training mode and finish  the game.  
 Oni Shooting game:

 Beat the game on Normal. 
 Ultimate mode:

 Beat the Oni Shooting  game.  
Adventures of Heihachi mode:

 Beat the game on any difficulty to play as Heihachi.  
 Original Onimusha swords: 

 Beat the game and acquire all three items from the Phantom Realms. Now start a new game to play with all three swords from the original Onimusha. 
 Bishamon sword:

 Beat the game with Onimusha rank, or pick it up in the Phantom Realm in Honnouji. 
 Ako's Black Haori:

 Beat Issen/Oni training. 
Michelle's alternate costume:

 Beat the game on Normal.  
 Michelle's second alternate costume:

   Beat the game with Onimusha rank, or play the game with a memory card   inserted containing  a saved game from Onimusha Blade Warriors.  
 Jacques' alternate costume:

   Beat the game on Normal with Jacques and get a high score, or beat the   game with Samanosuke's alternate costume. 
 Samanosuke's alternate costume:

   Beat the game on Normal with Samanosuke and get a high score, or beat the   game with Jacques' alternate costume. 
 Panda costume:

   Beat Secret Training mode, or play the game with a memory card   inserted containing  a saved game from Onimusha Blade Warriors.  
 Alternate ending:

   Max out  all seven Haori of Ako.
 
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