Juana (フアナ, Fuana) is the current-ruling queen of Tres España and the vice-president and treasurer of the student council of Alcalá de Henares, Tres España's academy. She is also part of the Eight Great Dragon Kings as the owner of one of the Mortal Sin Armaments, Akēdia Katathlipsē.
Juana has the appearance of a mature woman, with a well-endowed figure, long blue hair and emerald green eyes. Her position is reflected well on her attire, which consists of a red dress with gold accents and decorative plates adorning her shoulders and waist, which makes her appear larger than her subordinates. Juana also wears a brimless cap that is much higher than a normal student's, also reflecting her status as a higher official.
She is described as having the look of a female teacher.
As one of the highest-ranking students in Tres España, Juana develops a strict personality when it comes to the implementation of the law of the Testament Union, following it to the letter. She is often calm and collected, and has an intellectual side to her, although she can also be airheaded.
She often reprimands Felipe Segundo, but she continues to be an excellent subordinate and a constant source of support to him despite this.
Three weeks after the defeat of Muneshige Tachibana in the hands of Musashi's Futayo Honda, she gathers the members of Alcalá de Henares' Student Council and Supreme Federation in a meeting wherein further actions are deliberated. She later announces the dismissal of Muneshige Tachibana from Alcalá de Henares' Student Council.