Ulysses: Jeanne d'Arc and the Alchemist Knight is an anime set during the Hundred Years' War, focusing on Montmorency, a young and talented alchemist who dreams of becoming a great knight. In his pursuit of greater power, he becomes involved in a risky magical experiment that inadvertently alters his fate. His journey takes an unexpected turn when he encounters Jeanne, a mysterious girl with a special connection to the Philosopher’s Stone, a powerful artifact that could change the course of the war.

As Montmorency and Jeanne's paths cross, they become entangled in the struggles of the French army against the English invaders. Jeanne is believed to have divine powers, which makes her a figure of hope for the French people. Alongside their allies, including the fierce warrior La Hire, Montmorency and Jeanne face various battles, not only on the battlefield but also against those who seek to manipulate Jeanne's powers for their own agendas.

The anime blends historical events with elements of magic, politics, and personal conflict. As Montmorency and Jeanne grow closer, the series explores their complex relationship, as well as the consequences of seeking power through alchemy and the Philosopher’s Stone. The story is filled with action, intrigue, and moral dilemmas, offering a unique take on the legend of Joan of Arc while incorporating fantasy and adventure elements into the historical narrative.