In Warriors orochi there are unique items. I have found two.
On bai di castle, I start off by going to where the boulders fall and take out the lead engineer. Then I go down and defeat Kotaro Fuma. Then I take the route to the south gate of the castle, killing the arro machines (arbalests) as I go. Once I get into the castle, I kill the snake guy who says something like 'by the time were done with you, youll look like porcupines' and ambushes you with archers. Then the item appears in a box in the exit of the stone sentinel maze. Do all this Quickly.
On the 7th level on shu, I just ran around killing oficcers and when I got into the bit with 3 floors (or 2 I can't remember) got in and out as quickly as possible. The item appeared in the far south east of the castle.
I have unlocked everyone. Orochi is stronger at lv 20 than Kotaro Fuma At 99.