Tidus

Tidus is a minor character in the Kingdom Hearts series, originally from Final Fantasy X. He is voiced Shaun Fleming in the English version of Kingdom Hearts and Masakazu Morita in the Japanese version.

Kingdom Hearts
Tidus is a friend of Sora, Riku, and Kairi, and is a resident of the Destiny Islands, spending most of his time with Wakka and Selphie.

If Sora loses a practice battle with Tidus on the second day in the Destiny Islands, Tidus performs his victory pose from Final Fantasy X, namely, tosing his sword upward then catching it before swinging it to his side.

Kingdom Hearts: Chain of Memories
In Kingdom Hearts: Chain of Memories, Tidus appears with Wakka and Selphie in both Sora and Riku's stories as part of the memory-based Destiny Islands in Castle Oblivion.

Kingdom Hearts II
He does not appear in Kingdom Hearts II, but Selphie mentions that he an Wakka are "All wrapped up in their ball game," which, if he's anything like his original incarnation, is Blitzball.