Namco Bandai hasn’t announced Naruto: Ultimate Ninja Heroes yet, but EB Games has a page explaining what is supposedly in the PSP game.
Play Your Favorite Rivalry Through the Ultimate Team Mode: Choose from 20 powerful ninja to form your favorite ninja team from the show or create your original dream team!
Team Based Skill System: Try out a wide variety of different team combinations to awaken the hidden skills that lie within each character! Even one character will bring about a different set of skills depending on different character combinations.
Battle Your Foes Anytime, Anywhere!: Engage in 1 vs 1, 3 vs 3, 1 vs 3 battles, share your game and trade your character profile with your friends via Wi-Fi LAN connection anywhere, anytime!
Upgrade Your Favorite Character: Customize your favorite character to give you an edge in battle. Earn Training Points towards upgrading each character’s strength, defense, chakra, agility and even special abilities. You can also trade your profile with your friends via Wi-Fi LAN connection.
Become the Ultimate Hokage!: Put your ever-growing skills to the test on rewarding missions and rise in the ranks of the ninja to become the Ultimate Hokage!
20 characters? The Japanese release had 23 after unlocking all of them. Maybe the EB Games page is keeping the other 3 characters as a “secret”. There’s also lots of emphasis on the “team” system where you explore the mysterious tower with a squad leader and three other characters. Skills let you pass through the dungeon faster by breaking walls and spotting hidden passages. The minor details about Naruto: Ultimate Ninja Heroes makes the game sound like Naruto: Narultimate Hero Portable. However no details were given about the story or the “make your own labyrinth” system which some gamers loved and others loathed.