We got your Naruto Ultimate Ninja cheats right here, enjoy!

Unlockable Characters
Defeat story mode playing as any character: Neji Hyuuga
Defeat story mode playing as Neji Hyuuga: Hinata Hyuuga
Defeat story mode playing as Hinata Hyuuga: Haku
Defeat story mode playing as Haku: Zabuza Momochi
Defeat story mode playing as Zabuza Momochi: Gaara
Defeat story mode playing as Garaa: Orochimaru

Hidden Scrolls
Here are the locations of the hidden scrolls for the first S rank mission. You can obtain these in any mode, but practice mode is the easiest.

Ramen Shop (foreground) - Hit the lanterns so each of them grows red.
Hokage's Statue Stage (foreground) - Jump repeatedly on the tree to the left.
Zabuza's Home (background) - Wait 3 seconds on the game clock while standing on the balcony.
Bridge (foreground) - Wait 3 seconds on the game clock while standing on the boat.
Yagura map with the Giant Frog & Snake (background) - ump from the top of the frog to the snake, then jump back.
Chunnin Testing Stage (foreground) - Run through the tunnel from the left entrance and exit the right. Repeat 3 times.
Hero's Gravestone (any) - Attack your opponent's support character 5 times.
Survival Stage (background) - Destroy the doll on the right 10 - 15 times.
Wind Clan (foreground) - Keep attacking the vending machine until the scroll shows up.
Tornado Sand Map (background) - Destroy 8 objects flying within the tornado.
Nightly Rooftop Map (background) - Stand on the tail of the right fish statue until the scroll appears.
44 Forest of Death (foreground) - Attack the fish on the left 3 times.

Additional Rank S Missions
Mission #11 Finish Icha Icha Paradise (99 times each pair) - Complete S Rank Mission #2 Icha Icha Paradise
Mission #12 Collect 9,999,999 worth of money - Finish all non-S rank missions (Hokage Rank)

Unlockable Stages
2 Village of Sand stages - Beat Gaara's story mode
Great Naruto Bridge - Comeplete Haku's Story
Zabuza's Hideout - Comeplete Haku's Story
Kazekage's Mansion - Comeplete Gaara's Story
Sumanigo Estate and Buddha Statue - Comeplete Gaara's Story

Capsule Machines
Capsule Machine for Collectors - Achieve the rank of "Chunnin"
Capsule Machine for Maniacs - Achieve the rank of "Anbu"

Play in a different colored outfit for any character
Press and hold L2 and R1, then press X (only works for FREE BATTLE & MISSION modes)