Fuu Hououji, meaning "Wind of the Phoenix Temple," is one of three protagonists summoned from modern Japan to Cephiro. A student at a school for gifted children, she meets her companions during a Tokyo Tower school trip, showing early kindness by giving Hikaru a spare token. She remains calm upon arrival in Cephiro and facilitates introductions.

Her appearance features chin-length sandy blond hair with short bangs, green eyes, and round glasses. She wears her school uniform (green jacket, skirt, white petticoat, red accessories), initial white-and-gold emerald-studded armor upon summoning, and evolved green feather-resembling armor. This reflects her reserved, analytical nature.

Fuu acts as the group's strategic center, relying on logical thinking and book-smart intelligence. She rarely panics, methodically assessing situations—often likening Cephiro's trials to a role-playing game. Her personality blends polite formality with bluntly stating the obvious, creating humorous friction with Umi. Despite self-doubt, she draws strength from unwavering belief in her friends. Her school archery club informs her initial weapon skill.

Her primary character arc centers on her romantic relationship with Ferio, Princess Emeraude's estranged brother. They meet in the Forest of Silence, where she persuades him to become their bodyguard. Key media divergences exist: in the anime, she saves him from petrification using a borrowed bow, affirming self-belief; in the manga, he gifts her a ring, visibly flustering her. Later, she grapples with guilt over Emeraude's death, but Ferio's feelings remain steadfast. Their bond deepens in the second arc, marked by her distress during brief jealousy over another girl under his protection.

Pivotal standalone moments define her development. Captured by Fahren's forces, she challenges its ruler, Lady Aska, to an archery contest for freedom. Her victory secures release, forges a friendship with Aska, and prompts Aska to reconsider ambitions. Fuu later participates in the final battle against Debonair, aiding Cephiro's restoration before returning to Earth. She processes grief internally while maintaining outward normalcy.

As the Wind Knight, her magic emphasizes defense and healing, contrasting her companions' offense. Spells include "Winds of Healing" for recovery, "Emerald Typhoon" for attack, "Winds of Admonishment" for immobilization, and "Winds of Protection" for barriers. The anime-exclusive "Emerald Cyclone" is her strongest attack. She wields a broadsword made of Escudo, magically lightened for her use despite her stature. Her elemental affiliation connects to her phoenix-like Rune God, Windam. Its revival highlights a defining choice: forced to select between Windam's power and Ferio's life, she chooses Ferio, validating her compassionate resolve.

In the OVA continuity, Fuu plans to move abroad with her parents and plays piano in her school's music club. This version depicts her as less polite and more adversarial, controlling Windam against Ferio during Cephiro's invasion of Earth.

Trivia notes her color scheme (green, ironically associated with earth), her sword's disproportionate size in the manga, and her RPG comparisons during the quest. She has an older sister named Kuu.