Yuna was designed by character designer Tetsuya Nomura. Artwork of Yuna was drawn by Nomura and Yoshitaka Amano.
Final Fantasy X
Born in Bevelle and brought up on the island of Besaid, at the start of Final Fantasy X, Yuna is a reserved, intelligent and serious girl whose formal attire contrasts sharply with Tidus' more outgoing appearance. Yuna is a summoner of Yevon and has the ability to summon powerful creatures known as "aeons." She is mild in demeanor and soft-spoken, but harbors no doubt in herself or in her mission to destroy Sin, and usually manages to conceal any feelings of sadness from others. She is also half-Al Bhed on her mother's side, and consequently has heterochromatic irises: one blue and one green.
As a summoner, Yuna travels across Spira to end the threat the malevolent force Sin poses to her world, aided by her aeons, and even more so by her guardians, whose duty it is to protect her along her journey. Yuna begins her pilgrimage across Spira with three guardians: Kimahri Ronso, who took care of her after she was orphaned; Lulu, who treats her as a younger sister; and Wakka, with whom — along with Lulu — she has been close friends since childhood. After Tidus arrives in Besaid, she takes him as her fourth guardian, and later, Auron — who was also guardian to her father — becomes her fifth. Finally, Yuna's maternal cousin Rikku becomes Yuna's sixth and final guardian shortly after Tidus and Wakka thwart her attempt to kidnap Yuna with an underwater machina.
During the course of the game, Yuna is forced to grow in character. She becomes battle-hardened and her Yevonite beliefs are shaken and eventually shattered. Furthermore, her ever-growing relationship with Tidus causes her to question her quest, and think more for herself. This is evident when she is composing the video sphere she intends for her friends and guardians to view after her death- she confesses that the thought of not being with Tidus scares her.
As she learns more about Sin — against whom she has trained in the summoners' arts to use the Final Summoning — Yuna becomes caught up in the plot of Maester Seymour Guado, who claims to want to unite Spira by marrying her, but who seeks to use her to become the next Sin and crush Spira. Yuna had planned to marry him in exchange for him turning himself over to Yevon's judgment - the plan fails and Yuna and her guardians, recently informed of Seymour's crime, fight and kill him.
She is later kidnapped by Seymour's henchmen and brought to Bevelle, where her guardians launch a rescue attempt that ends in their capture. When she discovers that the Church of Yevon uses machina, violating its own teachings, and that it has no intentions of allowing her to send Seymour despite his evil intentions, her faith in Yevon is finally crushed. When Tidus eventually learns the full implication of the Final Summoning — that Yuna will sacrifice herself, as her father did, in order to bring about a temporary period free of Sin (called "the Calm") — his perspective persuades her that they can find another, more permanent way to rid Spira of the threat of Sin.
Tidus and Yuna's mutual love for one another intensifies as the party approaches its destination. In the romantic setting of a sphere pool in Macalania, Tidus shares memories of his native Zanarkand and toys with the idea of showing Yuna his home (even though it is becoming clear that he can never return). Yuna realizes she will never live to see it, and the burden she has been carrying in silence for so long finally causes her to break down, and she starts crying uncontrollably. Tidus moves to comfort her, and they passionately kiss. In the morning, Yuna has little choice but to proceed with her pilgrimage. When the quest draws to a close, Yuna is shocked to discover she must sacrifice one of her guardians to provide the soul for the Final Aeon, and that as the Final Aeon will become Sin, the Final Summoning can never defeat it.
With Tidus's encouragement, she decides to break Yevon's endless cycle and find another way to defeat Sin, one which will not provide it with the means to rise again. This eventually leads to a confrontation with Sin and the true progenitor of Spira's sorrows, Yu Yevon. Yuna's group defeats Braska's Final Aeon, whose fayth is Tidus's father Jecht, and after defeating Yuna's aeons as Yu Yevon possesses them, defeats Yu Yevon himself. However, as a consequence of defeating Yu Yevon and ridding the world of Sin, Tidus broke Yu Yevon's hold on the fayth, resulting in Tidus vanishing into nothingness as the fayth wake up. Before he leaves for the Farplane, Yuna tells him she loves him (in the Japanese version of the game, she says "Thank you" instead, basically thanking Tidus for protecting, supporting, and loving her).
In Final Fantasy X International, an extra scene called "Eternal Calm" recounts Yuna's thoughts two years later as she tries to return to her normal life back in Besaid. As the high summoner who permanently defeated Sin, Yuna is constantly plagued by visitors and tourists. More than once, she is told by the elders of her town that she should be considering marriage and settling down. As Yuna contemplates the changing Spira and her role in it, Rikku comes to visit, showing her a sphere Kimahri found that she believes shows Tidus. Feeling that she deserves an adventure of her own, Yuna literally runs off with her cousin without a word, fueled by hope that she may be able to find out more regarding Tidus.
Final Fantasy X-2
After leaving Besaid, Yuna undergoes a total makeover, complete with a new outfit. From there, she sets out as a sphere hunter (a new craze sweeping Spira), becoming a member of the Gullwings to learn more about the sphere that features a young man with a strong resemblance to Tidus confined within a prison cell. The Gullwings' members include Rikku, a mysterious young woman named "Paine," an Al Bhed child prodigy named "Shinra," Rikku's brother Brother, and his friend Buddy. Together with Rikku and Paine, the trio of girls are known as "YRP" ("YuRiPa" in the Japanese version). In the opening intro of the game scene, her Garment Grid and Songstress Dressphere are stolen by Leblanc, who subsequently uses it to impersonate Yuna. While Rikku and Paine attempt to stealthily get the grid back, Yuna is forced to use the Gullwings' "prized" Mascot dressphere until her presence was required. By that time, Yuna, in her gunner dressphere, shows up with Rikku and Paine. Together, the Gullwings defeat Leblanc and her chief honchos, Ormi and Logos.
Yuna displays some changes in personality in Final Fantasy X-2: while still very kind-hearted and serious about her duties and putting others first, Yuna is more open and direct. However, her friends still occasionally tease her about her habit of being a pushover, for she can never turn her back on anyone's request for some form of aid, such acts of charity as these comprising the majority of the game's side-quests and missions. Her relationships from Final Fantasy X have given her a new look at life and – freed from the responsibilities and restrictions of her former role as summoner – she is presented as a much more free-spirited person. She also regards Rikku as something of a role model, picking up on her eccentric expressions, which included "disasteriffic" and "oh, poopie!"
Her purpose for traveling with the Gullwings, however, is mainly because she hopes to find more spheres that would link with the one Kimahri found, what she hopes is a clue that Tidus is alive. Her investigations eventually lead her into the plots of Shuyin and the various opposing factions in the post-Sin Spira, particularly those of the Youth League and New Yevon. The Gullwings in general – and Yuna in particular – seek to restore some sense of unity and peace to a dangerously divided world, as well as to stop forces which would seek to damage Spira even further. The player's actions throughout the course of the game determine whether or not Yuna ever manages to reunite with Tidus, a gift to her from the fayth as thanks for having saved the world a second time.
Yuna, along with Rikku and Paine, appears at Hollow Bastion in Kingdom Hearts II, working for Maleficent as spies/agents in return for treasure. The three are fairy-like and appear super deformed. After Maleficent abandons the three during the Heartless attack at Hollow Bastion, and led to believe Leon has treasure by Donald, Yuna and gang switch their alliance to Leon and the rest of the Hollow Bastion Restoration Committee. Yuna and others forgive Sora and his partners for the deception with the three giving Sora the "Gullwing" Keychain, a reference to their sphere hunting group in Final Fantasy X-2. She was the only character in her gang whose name is spoken, "Yunie," a nickname made up by Rikku (only in the English version of X and X-2). Yuna, in both her summoner and gunner forms, is a playable character in Itadaki Street Special.