Naruto Shippuden: Ultimate Ninja Storm 4 has a ton of fighters (over 100 of them). And, like most fighting games, there are alternate costumes you can obtain for many of the characters.
Instead of earning the costumes through simple gameplay, you’ll have to purchase them from the Bandai General Store located under Collection. Choose the Ninja Treasure Exchange option (there are no costumes in the basic Ryo store), and then scroll all the way down until you see costumes.
As soon as you enter the store, you’ll see that costumes require more than just Ryo to purchase, you’ll also need a set amount of three different Ninja Treasures. These are obtained through playing the game, whether through multiplayer, survival, story, or adventure.