Yuna was designed by Final Fantasy X character designer Tetsuya Nomura. The basis for Yuna's overall design was that of Okinawan kimonos, but Nomura has also mentioned that when he learned the character was to perform a dance called the "sending," he wanted to give her outfit something that would flow. For this reason, the specific type of kimono he chose for her was a furisode, a kimono bearing long sleeves. Nomura has explained that he adorned Yuna's dress and necklace with images of the hibiscus flower also called "yuna," and that her name carries the meaning of "night" (夕な) in Okinawan, establishing a contrast between her and the lead male protagonist of Final Fantasy X, Tidus, whose Japanese name (ティーダ) translates to "sun" (太陽) in Okinawan. This contrast is also represented in-game by items named for the sun and moon that empower Tidus' and Yuna's most powerful weapons. Nomura has explained that while all these subtle details may be unnecessary, he wants his designs to have meaning behind them. Yuna has heterochromia, a condition that gives the subject two different colored eyes; in Yuna's case, her blue eye comes from her half-Spiran ancestry while her green eye comes from her half-Al Bhed ancestry.
The fan reaction to Final Fantasy X convinced the developers to continue the story of Yuna and other characters with Final Fantasy X-2. Tetsu Tsukamoto, costume designer for Final Fantasy X-2, states that the radical design changes for Yuna from one game to the other reflect a huge cultural change. Yoshinori Kitase, producer of Final Fantasy X-2, added that they did not want to make X-2 feel like an extension of its predecessor, so they changed the clothing of Yuna, Rikku, and others' to make them seem more active. This was accomplished before the story and setting were created. Because Yuna, Rikku, and Paine live in a more care-free world, the designers wanted them to be able to dress up, a feature which became key to the game's gameplay. Kazushige Nojima, scriptwriter for X-2, described her new outfit as a "natural reaction to the heavy stuff she wore in FFX". Yuna's singing performance was used to demonstrate the pop feel that X-2 incorporates.Appearances
Final Fantasy X's system has her use healing magic in the game, while also allowing her to summon powerful magical entities called "aeons." Already known throughout Spira as the daughter of High Summoner Braska – the man who, ten years earlier, brought a brief respite from Sin's destruction (The Calm) – Yuna has chosen to embark on the summoner's pilgrimage to become a High Summoner herself. The burden of this responsibility is expected to see Yuna journey to temples across Spira, acquire the aeon from each and ultimately summon the Final Aeon in a battle that will claim both its life and hers. Her weapons are a variety of staves, and she is able to summon ten aeons during the game. As Yuna's story progresses she gradually becomes more open and falls in love with Tidus. Because Yuna's mother was an Al Bhed she has heterochromia, so one of her eyes is green and the other blue, a reflection of her mixed heritage. Despite this, she is never heard fluently speaking the language (give or take a few phrases), probably due to the fact that her mother died at sea by Sin when she was at an early age. Yuna returns in Final Fantasy X-2 (set two years after Final Fantasy X) as the lead protagonist, and is now nineteen, prominently featured as a Gunner. In X-2, Yuna journeys Spira in search of truth (and hopefully a long lost friend). She is more outgoing but also nostalgic. She is deeply saddened by the fading of Macalania Woods and greatly offended by the exploitation of Zanarkand Ruins as a tourist attraction. She also has a very helpful and generous personality. She always helps people in need, although her job as a sphere hunter may make her intentions seem more money focused.