The Art of War, The Methods of the Sima, Six Secret Teachings, De Re Military, Thirty-Six Stratagems. Throughout history, the greatest tacticians of the world have employed deceptive tactics and stratagems to turn the tide of war in their favor. The study of the art of war has been refined throughout the centuries, and its culmination is the fine art of the Oshiro Shinobi, or Castle Ninja. Such ninjas use stealth and strategy to protect their charges.

Bo Jutsu - Art of the Staff
The oshiro shinobi gains Combat Expertise as a bonus feat, even if she does not meet the prerequisites. The oshiro shinobi is considered to be fighting defensively when using Combat Expertise.
This replaces poison use

Boryaku - Art of Strategy (Su)
At third level, when fighting defensively with a bo staff, an oshiro shinobi gains a +1 deflection bonus to her AC. This bonus increases by +1 at 6th level and every 3 levels thereafter (to a maximum of +6 at 18th level).
This replaces no trace

Anguo - Art of Signaling (Ex)
At 4th level, the oshiro shinobi can set up an alarm system of ropes and pulleys to alert her  and others to unauthorized entrants into a place of her choice.  The system acts as a non-magical alarm, except that the password is a gesture, switch, or other somatic component and the alarm must be audible. Setting up the system for the first time takes 1 round per 30 feet included in the perimeter, but resetting the systems take only 1 round. The DC of perception checks to spot this alarm system and of disable device check to disarm it is equal to 20 + the Ninja’s Cha modifier + 1/2 her level. This DC is set when the system is first installed.
This replaces uncanny dodge

Ho Jutsu - Explosive Arts
At 8th level, an oshiro shinobi may spend a ki point when setting up or resetting an alarm system to cause the alarm system to deal her sneak attack damage to the creature who sets it off. This damage is fire damage, instead of precision damage. A Reflex saving throw halves this damage (10 + the Ninja’s Cha modifier + 1/2 her level).
This replaces improved uncanny dodge