Pierre is a knight of the Girtonia Kingdom who serves as the guard knight of Mia Adenauer, the younger sister of the saint Philia. He belongs to the faction that supports the First Prince, Fernando Girtonia, and is personally attentive to Fernando's situation, since the prince is physically frail and largely confined to his room. Because of this allegiance, Pierre plays a supporting role when Mia begins investigating the events surrounding her sister's departure and searches for allies within the royal court. With his cooperation, Mia is guided to the room where Fernando is being kept, allowing her to speak with him directly. His role in the story is therefore connected to the political division inside the Girtonia royal family, which is split between supporters of the First Prince and the camp of the Second Prince, Julius, who holds practical authority over the kingdom. Pierre's motivations are rooted in loyalty to Fernando and concern for the prince's wellbeing, and his conduct reflects a knight's sense of duty. As a member of the royal guard, his capabilities are those of a trained knight entrusted with protecting the saint's sister.