Oscar François de Jarjayes is the central character of the anime The Rose of Versailles. She is born the sixth daughter of General Jarjayes, a noble military family that desperately wants a male heir. Her father decides to raise her as a boy, giving her the name Oscar and providing her with a military education. From childhood she is dressed in male clothing, trained in swordsmanship, riding, and command, and presented to the world as a man. Although she is a woman, she is frequently mistaken for a beautiful man, and the story treats her appearance as genuinely striking regardless of how others perceive her sex.

Oscar's personality is defined by pride, discipline, and an intense sense of duty. She is composed and commanding in public, but beneath her dignified exterior she is emotionally vulnerable and often lonely. She has a strong sense of justice, honesty, and compassion, and she treats the soldiers under her command with fairness rather than arrogance. Her upbringing among the aristocracy gives her privilege, but she is deeply aware of the suffering of ordinary people, and this awareness creates the central conflict of her life. She is torn between her loyalty to the monarchy and her growing sympathy for the common people, and she tries to follow her own moral code even when it places her in opposition to the court, her family, and the queen she serves.

In her military role, Oscar first serves as a colonel in the Royal Guard, responsible for the personal safety of Marie Antoinette at Versailles. She later becomes commander of the French Guards, a position in which she leads ordinary soldiers who admire her courage and integrity. Her duties place her in the difficult position of enforcing royal orders while her conscience gradually moves her toward the revolutionary cause.

Her key relationships shape her development. She is initially devoted to Marie Antoinette, and the two share a close friendship, but Oscar slowly becomes disillusioned with the monarchy's indifference to the suffering of the people even as she remains personally loyal to the queen. Her closest companion is André Grandier, the son of her nanny, who grows up beside her as her aide and confidant. André loves her deeply but conceals his feelings for years, and Oscar relies on him more than she openly admits. She also falls in love with the Swedish count Hans Axel von Fersen, but he loves Marie Antoinette, and this unrequited love deepens her loneliness and complicates her feelings about her identity and her place in the world.

Over the course of the story, Oscar develops from a loyal servant of the crown into a reluctant revolutionary. Her sense of justice and her firsthand experience of the people's hardship push her to question the social order she was raised to defend. In the end, she chooses to side with the revolutionaries and leads her French Guards to join the attack on the Bastille. She is gravely wounded during the assault and dies from her injuries, with André beside her in her final moments. Her death marks the end of an era and cements her as a figure caught between two worlds, never fully belonging to the aristocracy or to the revolution that ultimately claims her life.

Oscar's notable abilities lie in her skill as a swordsman, her excellence as a rider, and her natural talent for command. Her men respect her because she is brave, fair, and unwilling to abuse her authority. Her strength as a character comes not only from these abilities but from her willingness to question who she is supposed to be and where her loyalty truly belongs, making her one of the most memorable figures in anime storytelling.