The protagonist and player character of Avalon Code. Tia (ティア Tia) has been assigned the task of recording everything around her in the Book of Prophecy, becoming its new Chosen One in title. As such, she becomes gifted with the ability to read ancient runes; see and interact with Metalize (Recipe) Tablets, ghosts, and the Book Spirits; use any armament or equiment produced from the Book; and change the makeup of anyone or anything recorded in the Book. At one point in the game, she is given the choice to align with one of four legendary Weapon Schools.
Although Tia begins the game under the protective wing of fellow slum-dwelling pickpocket Rex and is seen to correspond frequently with the sickly townsgirl Fana, her past—including reference to any family members deceased or living—is largely left unelaborated. However, it can be assumed that she continues to live on with the Spirits in a home in the New World.
Judging by dialogue clues dropped by other characters, Tia is a native Kaleilan of approximately fourteen or fifteen years. She is of middling height and has bobbed strawberry blonde hair as well as large hazel eyes.
She wears a signature dark pink (or vintage red) embroidered overcoat which may or may not be a waist-length variant of the traditional justacorps , striped jacket, long-sleeved white undershirt trimmed with frills, short plaid skirt, dark gray tights, and pointy-toed leather boots which seem to combine the structure of spats into the shoes themselves.
For accessories, she also has a small quatrefoil hair clip worn above her right ear, golden yellow scarf, leather chest strap that may connect to a pouch or sheath not seen in the official art, and an enameled quatrefoil belt. It is unknown to what extent her dress reflects her station in life.
- "A girl who speaks her mind. The main character if the player chooses to be female. Although a little naïve, she always carries out what she puts her mind to."
- - Avalon Code official English instruction booklet
Because Avalon Code puts the player's choice of hero to use in mostly aesthetic ways, the events of the story--including the main character's actions and reactions--remain exactly the same whether running the campaign as Tia or Yumil. This is not to say that she lacks character. Though she values justice and exemplifies generosity, her sense of responsibility is her defining feature,
Her precise life circumstances are left extremely ambiguous by the writers; she is presumed to have carried on a quiet existence in the poor district of Rhoan Town for all her life, and a solitary one for most of that time. Not unusually, she tends to function on a microcosmic level, as evidenced by the extensive writing projects (letters to Fana and a high fantasy novel draft) scattered around her ramshackle dwelling. However, while she comes off as a hopeless dreamer to some and an unmotivated truant to others, she is extremely aware of her surroundings, majestic or mundane. It is likely that both this attention to detail and penchant for describing the world for the benefit of others factor into her eligibility for Chosen One.
On an interpersonal level, though she apparently did not stray far from home prior to the beginning of the plot, Tia is largely unafraid of "rubbing shoulders" with others on any level of society. She treats her world-renowned combat teacher the same as the misunderstood town witch, and neither pities herself for being poor nor shuns the rich for being on the opposite end of the spectrum. While she is wronged by both her thieving friend and the accusatory monarchy, she does not label them as "bad" people or try to change their questionable ways.
Despite her tendency toward trust, she can also be blunt--even cutting--when it comes to others' feelings. Additionally, depending on the player's reaction choices at key points, she may begin to externalize the results of the unfair treatment she recieves and the trials she undergoes.
Tia is portrayed as a silent protagonist, although the dialogue of the characters with whom she interacts strongly indicates that she is fully capable of normal speech. Interestingly, she is unable to view her own Book of Prophecy profile (likes/dislikes, aspirations, and personal history). In-game, her page is used to show the player's current status, including hit point and plana point totals, equipment, and inventory.
If the player chooses Tia as the protagonist, Yumil, her male counterpart, will never be encountered in the game.
- Tia's age is the cause of some confusion among fans of the English localization, as Grandpa Vis ambiguously states at the beginning of Chapter 5 that the decennialy-occurring Tournament which happens in the game will be her "first".
- Tia's name is close to that of the important Norse mythological figure Týr. The two do not share any other notable characteristics.
- Though the speed of the action remains the same for the sake of gameplay, there is a notable visual difference between Yumil and Tia's running gaits, Code Scanning leaps, and somersaults.
- Tia's overall visual design is similar to that of the Monica , a young girl character from the game Rune Factory 3. Contrary to popular belief, it is female illustrator Minako Iwasaki, rather than HACCAN , who does much of that series' official art; the resemblance is coincidental.
- In the Japanese-language version of the game, Tia's spoken lines were performed by acclaimed voice artist Mamiko Noto.