In an interview with Japanese media outlet 4Gamer, Zelda series producer Eiji Aonuma and Tri Force Heroes director Hiromasa Shitaka revealed that those who play local multiplayer in the upcoming Tri Force Heroes will receive a special extra. By playing locally with friends, players will receive an item called the “proof of friendship.” The amount of this item needed has not been revealed yet, but by using enough “proof of friendships” one can unlock a costume that will only be available to those to play with friends through the local multiplayer mode. Tri Force Heroes allows three people to play the game through one game cartridge due to the 3DS’s Download Play, so you won’t need three people to actually own the game to play together.
“4Gamer: I’ll change the subject a bit, but please tell me about a matter that is on my mind. You need items called “proof of friendship” in creating a special costume, but can you get those in single player?
Shikata: You get them only if you play together with other people locally or with Download Play.
Aonuma: Generally speaking, you’d want to play the multiplayer. This time everyone can play with just one copy of the game via Download Play as long as you have three systems. Playing noisily with other people is the greatest flavor of this Zelda and you’d want to experience it. I think it can be hard to gather people if you’re an adult, but I’d like people to try to come and play together in order to collect proofs of friendship.”