In 18th century Paris, a coffin is found floating down the Seine River. It carries the corpse of noblewoman Lia de Beaumont: a spy of King Louis XV, and whose younger brother Charles d'Eon has just been knighted. When several disappearances occur throughout Paris, the young knight believes that they are somehow connected to his sister's death. Hoping to find her killers, d'Eon joins the secret police to investigate the incidents. Following the clues, they piece together that a conspiracy between members of the French and Russian nobility, spurred on by a cult, may be behind the disappearances. D'Eon concludes that Lia may have uncovered the truth while on a mission and was killed as a result. That night, the secret police are to arrest the Duke of Orléans on suspicion of being the mastermind. One of their own transforms into a demon called a Gargoyle and massacres the group. D'Eon attempts to rescue the sole survivor, only to find that he too has been transformed. During the ensuing battle, d'Eon is possessed by Lia's vengeful soul, who takes command of his body and slays the Gargoyle herself. In the aftermath, d'Eon must gather allies to discover the depth of this supernatural conspiracy.

Even though he is the top salesman at his company, Keiichirou Tachibana decides to quit his job to open a bakery. While looking over résumés for a head patissier, one name sticks out in particular: Yuusuke Ono, the young man who confessed his feelings to Keiichirou in high school—and whom Keiichirou harshly shot down. Now, Yuusuke is known both as a genius patissier for his skills in the kitchen, and for possessing a demonic charm that attracts even straight men into his bedroom. Despite their shared past, Keiichirou hires Yuusuke and starts working on making the bakery a success. Before long, the pair is joined by former boxer Eiji Kanda, who is searching for a new career after an injury forced him to retire early. Everything is looking up for the newly-opened bakery named Antique—but the ghosts of the employees' pasts threaten to upset their simple lives.

Nestled away on the rooftop of Tenikai General Hospital is the unconventional Department of Investigative Pathology headed by the eccentric Dr. Takao Ameku. The tiny department, consisting of Takao and her sole resident Yuu Kotori Takanashi, treats complex cases that most other departments within the hospital cannot resolve on their own. The mystery-obsessed Takao always tries to insert herself into cases that capture her fancy—much to the dismay of her colleagues and the police. Even if her meddling creates more problems for the hospital and those around her, none can deny the brilliance that the young department head exhibits as she weaves a diagnosis together. No matter the specialty, no case is impossible for Takao and a somewhat reluctant Takanashi to solve.

Nanoha Takamachi, an ordinary third-grader, loves her family and friends more than anything else. One day, after having a strange dream in which a ferret gets injured, she sees the very same ferret in real life and rescues it. That ferret turns out to be Yuuno Scrya, a mage from another world who is trying to capture the 21 scattered Jewel Seeds before they cause serious damage to the universe. Yuuno is not powerful enough to capture the Jewel seeds on his own, so he grants Nanoha the intelligent device Raising Heart and begins training her as a mage. Unfortunately, the powerful Jewel Seeds attract those with ill intentions. Another mage, Fate Testarossa, is desperate to collect the seeds for some unknown and sinister purpose, though the solemn look in her eyes makes Nanoha think that there is more to Fate than meets the eye. Mahou Shoujo Lyrical Nanoha: The Movie 1st is a retelling of the original series, which tells the story of two young mages and how their strong emotions shape their actions.