The driving force of Spira is the religion of Yevon. Adherents of Yevon are fervently opposed to the use of advanced technology (which they refer to as "machina"), and lead the fight in the perpetual war against the entity known as Sin.

Although the majority of Final Fantasy X's story takes place in the world and era of Spira, it begins in Zanarkand, the city that never sleeps. Tidus, a native of Zanarkand, is a 17-year-old blitzball star. When Zanarkand is suddenly attacked by an evil force known as Sin, Tidus fights alongside the mysterious character Auron against a fragment of Sin, a Sinspawn. While they are victorious, they are both sucked into the vortex of Sin's power, and Tidus wakes in the midst of ruins of a mysterious temple. Tidus learns he has been teleported to Spira, a world different from, but connected to, his Zanarkand.

Tidus is picked up by a group of Al Bhed, who speak a substitution cipher of his language (which can be translated by collecting items in the game), and who freely use machina as they are exiled by Yevonites. He meets the energetic young Al Bhed girl Rikku, who is the daughter of Cid, leader of the Al Bhed. Rikku speaks his language, and informs Tidus that Zanarkand was destroyed a millennium ago. Tidus is incredulous, and Rikku tells him since he was in contact with Sin he must be suffering the adverse effects of Sin's toxin. Tidus is brought aboard the Al Bhed ship, but after only a short time is swept out to sea in another attack from Sin.

     This time, Tidus is washed up near the small town of Besaid, where he meets Wakka, apparently a blitzball player and captain of the local team (the Besaid Aurochs). Wakka takes Tidus with him to the town, where he is introduced to most of the rest of the playable cast through various levels of blundering explained away by Tidus's "amnesia". Yuna (of Bevelle, and daughter of High Summoner Braska) has just completed her initiation as a summoner of Yevon, one who is charged to defeat Sin. She sets out on her quest, along with guardians Wakka, Lulu (also of Besaid), and Kimahri Ronso (of the Ronso tribe). Later, the guardian Auron (the one who fought alongside Tidus in Zanarkand) joins the party, as does Rikku of the Al Bhed.

     Tidus soon learns that the Zanarkand he is from was destroyed some thousand years in the past. Sin was forced into remission ten years ago, by a force comprised of High Summoner Braska, the warrior Auron, and Jecht. Tidus wonders if the Auron he knows could possibly be the same in this new era, and if the man called Jecht could actually be his father, assumed dead at sea ten years before (from Tidus's perspective of time). Ultimately, the party must confront Sin, unravel the mysteries of its perpetual return, and figure out exactly how Tidus and his father Jecht fit into this mystery.

YUNA

AURON

KIMAHRI