Enter these codes at the pause menu during a mission. They can only be used after beating the mission 'Finale:Ephemera' and only one code can be used once per mission.

Invincibility Mode: Makes you and all NPCs invulnerable to any type of damage besides stealth kills which now only do 50% damage.: Right, Right, Down, Up, Up
One Hit Kill Mode: Makes you and all NPCs die in one attack. Item damage and most projectiles do not count.: Up, Up, Down, Right, Up
Restore Health: Restores all your HP but only once.: Up, Right, Right, Down, Left
Unlimited Items: Down, Left, Right, Up, Down

At the inventory screen prior to beginning a mission, press the d-pad five times in one direction to access these alternate inventories. NOTE: You must have beaten the Finale: Ephemera mission first. This works on both EU and JP versions of Shinobido: Homura.

Down 5 times: Black Ninja Flame (1), Explosive Sushi +300 (5), Powerful Land Mine (5), Cicada Shell (1)
Left 5 times: Short Grapple Hook, Strength Potion +90 (10), Knockout Sushi +90 (10)m Speed Potion +90 (10)
Right 5 times: Grapple Hook, Asuka Shuriken (30), Weak Land Mine (10), Health Potion +60 (20)
Up 5 times: Default mission inventory