Tenchu

USA NTSC version

Increase Item Capacity to 99
On the Items Screen -
L, L, D, D, S, S, T, S while holding the L1 button.

Unlock All Hidden Items
On the Items Screen -
L, L, D, D, S, S, T, C while holding the R1 button.

Increase Item Inventory
On the Items Screen -
L, L, D, D, S, S, T, X while holding the L2 button.

Restore Health
On the Pause Screen -
L, L, D, D, S, S, T, S.

Unlock All Levels
On the Mission Select Screen -
L, L, D, D, S, S, T, S while holding the R2 button.

*Enable Japanese Voice Over
On the Mission Select Screen-
L, L, D, D, S, S, T, C while holding the L1 button.

*Enable Enemy Layout Selection Screen
On the Mission Select Screen-
L, L, D, D, S, S, T, X while holding the R1 button.

*Enable Ayame Sexy Armor
You must be playing as Ayame.
At the item selection screen with armor displayed as an option enter -
L, L, D, D, S, S, T, C
If the command is entered successfully the number of available armor will drop from 1 to 0.

* indicates new cheat that was not present in the Japanese version.