This is from the in-game "Shinra's Dossier" - note that there are spoilers.

Yuna

A young lady once willing to throw all she had away to defeat Sin. But is the new Yuna prepared to do the same should she stand against Vegnagun?

Rikku

A girl troubled by Vegnagun, but even more troubled by Yuna's reaction to this new menace. Is Yuna Prepared once again to give her life for Spira? Rikku would not approve.

Paine

Once a recorder for the Crimson Squad, and also an old friend of Nooj, Baralai, and Gippal. She joined the Gullwings hoping to find answers to why the Squad collapsed.

Nooj

Meyvon of the Youth League, and once a candidate for the Crimson Squad. His pursuit of Venagun has taken him far from the adoring Leblanc.

Baralai

Praetor of New Yevon, and once a candidate for the Crimson Squad. He has retreated deep into the farplane along with Vegnagun.

Gippal

Leader of the Machina Faction, and once a candidate for the Crimson Squad. His pursuit of Vegnagun has led him into the deepest reaches of the Farplane.

Leblanc

A sphere hunter and leader of the Leblanc Syndicate. Could she be the sword foe of the Dull-er, Gullwings?

Ormi

A sphere hunter and member of the Leblanc syndicate. He is fiercely devoted to Leblanc, who he calls "the boss."

Logos

A sphere hunter and member of the Leblanc Syndicate. He would gladly give anything and everything for Leblanc.

Brother

Rikku's older brother and leader of the Gullwings. He learned our language out of the desire to speak with Yuna, but when he's overly stimulated, he slips back into Al Bhed...

Buddy

Brother's Childhood friend, and for all intents and purposes the Gullwings' Number two. As down-to-earth as he may be, from time to time he says things really out of this world

Shinra

An Al Bhed wunderkind. Underneath that mask, is he pondering his next invention...or Spira's future?

Barkeep

A hypello who has worked aboard the Celsius since brother took him in. His most likely unremarkable past remains shrouded in mystery.

Wakka

A blitzball player who once served as Yuna's guardian. With the fierce battle against Sin behind him, Wakka is now bracing himself for the fiercer battle of fatherhood.

Lulu

A black mage who supported Yuna as a guardian, and more importantly, as a sister of sorts. She lives on Besaid island with her husband, Wakka.

The Aurochs

Besaid's blitzball team the Besaid Aurochs. It's members include Datto, Letty, Jassu, Botta, and Keepa.

Lucil

Former Crusader and Chocobo Knight. She holds the Youth league together admirably as Nooj's right-hand woman, but the group's explosive nature complicates her efforts.

Elma

Former Crusader and Chocobo Knight. She was quick to follow Lucil in joining the Youth League.

Clasko

Former crusader and Chocobo Knight. Calling him Spira's number one chocobo fan would hardly be an overstatment.

Yaibal

An officer in the Youth League and ardent admirer of Yuna. He has the unfortunate habit of not waiting for people to finish what they have to say.

Maroda

A young man who was once a guardian to Isaaru, his older brother. When the calm came, he parted with his brothers and joined the Youth League.

Beclem

A man dispatched by the Youth League to whip the Besaid Aurochs into shape. He loudly decries the ancient precepts established by Yevon.

Dona

A summoer who made her pilgrimage with her lover, Barthello. After the Calm came, she put down her staff and took up residence in Kilika Island.

Barthello

A young man who because a guardian to protect Dona, his lover. He greatly reveres the legendary guardian, Auron.

Shelinda

Former priestess of Yevon. After the fall of the emplates, she moved to Luca, where she now works as a news anchor for one of its sphere networks.

Cali

A girl who looked forward to Yuna's calm. Her love of chocobos is almost a match for Clasko's.

Tobli

Producer of many a show throughout Spira. Frequently defying the laws of Linguistics, Tobli tends to use twice as many words to say half as much.

Tromell

Attendant who once served two generations of Guado Leaders, Jyscal and Seymour. With the arrival of the calm he forsook Guadosalem and sought refuge in Macalania woods.

Cid

Leader of the Al Bhed, father to Rikku and Brother, and also Yuna's uncle. He just recently made his start in the tourism business - perhaps in the hopes of rebuilding his lost home?

Nhadala

An Al Bhed woman who heads up the excavation camp in Bikanel Desert. She has a knack for psyching people and putting slightly misguided determination into work.

Benzo

An Al Bhed boy. He is the one and only person able to converse with Cacti and cactuars.

Rin

An Al Bhed businessman whose travel agencies dot all Spira. He has recently expanded into other enterprises.

O'aka

More properly know as O'aka XIII. After a brief retirement from the peddling business, he returned to work with the coming of the calm.

Wantz

A merchant proud to be called O'aka XXIV. When his retired older brother impromptu return to peddling, Wantz lost his drive and eventually left home.

Kimahri

A young Ronso who has protected Yuna since she was very small. He now struggles to keep his wounded people aloft as their elder.

Garik

A young Ronso warrior whose friends were murdered by Seymour two years ago. As a result, he hates the Guado fiercely and stands against Kimahri's pacifism.

Lian and Ayde

Two Ronso children who left Mt' Gagazet in search of a way to heal Kimahri's horn.

Isaaru

A former summoner, he is Maroda and Pacce's straight-laced older brother. He fell victim to Yevon's manipulations and once fought Yuna in a battle of Aeons.

Pacce

Once a guardian to his brother, Issaru, along with Taro and hana, he now seeks fortune as the founder and captain of his own band of sphere hunters, the Kinderguardians.

Maechen

An old man who has gathered great wisdom from his travels throughout Spira, and simply loves to talk about it. Once he starts, however, he rarley remembers to stop...

Auron

A warrior who transcended death to keep his promise to a friend. Two years ago he helped Yuna seal Sin's fate and usher in the Calm before departing for the Farplane at last.

Jecht

A man who came to Spira from the dream City of Zanarkand. Yuna had no choice but to vanquish Jecht, who has become the fayth for the Final Aeon, and thus sin itself.

Braska

Yuna's father. He clashed with Sin 12 years ago with Jecht and Auron at his side, and gave his life summoning the Final Aeon.

Kinoc

One of the for maesters of Yevon. He established the Crimson squad in an attempt to regiment the Crusaders. He ultimately died at Seymour's hands.

Lenne

A songstress who lit the stage of Zanarkand one thousand years ago. She was also a summoner, fated to lose her life alongside her lover, Shuyin.

Shuyin

A young man consumed by a thousand years of Despair. He seeks to use Vegnagun's power to extinguish Spira.

????(Tidus)

Perhaps not the young man shown in the sphere that Kimahri discovered in Mt. Gagazet...