Lavie Head is the daughter of Georges Head and Rachelle Head and serves as the navigator, mechanic, and childhood friend of Claus Valca in the world of Prester. She is an outspoken and moody young woman with short brown hair and gray eyes, and she takes great pride in her lineage, which is most evident in her fierce protectiveness of the vanship she and Claus fly—a craft believed to have originally belonged to their fathers. Both of their fathers died while attempting to cross the Grand Stream, a dangerous atmospheric boundary that separates the warring nations, and this shared loss deeply shapes Lavie’s outlook and motivations.

Lavie is practical, resourceful, and spirited. Alongside her navigation duties, she is an excellent mechanic who keeps their vanship in top condition, and she also handles much of the cooking and daily care for Claus. Her personality is defined by a strong sense of independence and a love for the free, unbound life of a sky courier. She is openly reluctant to remain aboard the battleship Silvana after they deliver the young girl Alvis Hamilton, preferring the open sky and the ability to come and go as they please. She abhors the use of vanships for military purposes and strongly disapproves when Claus shows interest in becoming a combat pilot, viewing it as a betrayal of the courier lifestyle and a needless embrace of violence.

Her relationship with Claus is the emotional core of her character. She treats him as a dear friend and nearly a sibling, often nagging him out of bed or cooking for him, but there is an undercurrent of repressed romantic feeling. This becomes most apparent through her simmering jealousy when the skilled pilot Tatiana Wisla begins to take an interest in Claus. Despite her occasional stubbornness and ability to hold grudges, Lavie is fiercely loyal and will stand up for Claus and for what she believes in without hesitation.

Lavie’s role in the story is that of Claus’s partner and anchor. She is the voice of caution and practicality, often grounding Claus’s more adventurous impulses. As the narrative progresses and the focus shifts to the larger conflict between Anatoray and Disith and the machinations of the Guild, Lavie and Claus become witnesses to events far beyond their courier origins. Together they protect Alvis, eventually bearing witness to the release of the Exile and the revelation of a new world. In the aftermath, Lavie and Claus choose to settle in the new world, and in the manga continuation, they start a farm together on Earth.

Notable abilities include expert vanship navigation and mechanics, allowing her to keep their vessel operational in the most demanding conditions. She is also an accomplished cook, able to prepare meals that sustain them during long flights. Her strong will and protective nature are perhaps her greatest assets, enabling her to face danger and uncertainty alongside Claus without backing down.