Ashtar Ryu costume - Successfully complete Story mode on the Hard difficulty setting to unlock the Ashtar Ryu costume.

Bonus missions - At the Mission mode screen, press Up, Down, Left, Down, Right, Up, Square to unlock the five bonus missions that are include in the Collector's Edition.

Classic Ryuken costume - Successfully complete Story mode on the Normal difficulty setting to unlock the Classic Ryuken costume.

Hard mode - Successfully complete Story mode on the Normal difficulty setting to unlock the Hard difficulty setting.

Master Ninja mode - Successfully complete Story mode on the Very Hard difficulty setting to unlock the Master Ninja difficulty setting.

Mission mode - Successfully complete Story mode on the Normal difficulty setting to unlock Mission mode.

Ninja Dog mode - Intentionally die three times in a row. Answer "Yes" when Ayane asks "Do you really give up the way of Shinobi?" to unlock the Ninja Dog difficulty setting.

Very Hard mode - Successfully complete Story mode on the Hard difficulty setting to unlock the Very Hard difficulty setting.

Items and weapons - Give the indicated number of Golden Scarab to Muramasa at the shop to get the corresponding item or weapon:

Armlet Of Fortune: 40 Golden Scarabs
Armlet Of Potency: 5 Golden Scarabs

Dabilahro: 20 Golden Scarabs

Great Spirit Elixir: 35 Golden Scarabs

Jewel Of The Demon Seal: 45 Golden Scarabs

Life Of Gods: 1 Golden Scarab
Lives Of The Thousand Gods: 10 Golden Scarabs

Plasma Saber MkII: 50 Golden Scarabs

Spirit Of The Devils: 15 Golden Scarabs

The Armlet Of Benediction: 30 Golden Scarabs
The Armlet Of Celerity: 25 Golden Scarabs