From her hometown to her daily life on Kurken Island, everything surrounding Reisalin "Ryza" Stout is painfully ordinary. Despite being the daughter of a hardworking farmer, she would rather go on pretend adventures as she explores almost every corner of the island. However, the fact that it is against the local customs to venture off Kurken Island irritates her to no end. One day, wishing for something interesting to finally happen in her life, Ryza escapes on a boat with her two good friends: the bookworm Tao Mongarten and the aspiring warrior Lent Marslink. Arriving at a nearby forest, the trio stumbles into Klaudia Valentz, the daughter of a visiting merchant who also wandered off into the woods. As the naive and underprepared group ventures further, they run into dangerous monsters. Thankfully, they are rescued by the alchemist Empel Vollmer and his skilled bodyguard Lila Decyrus. This fateful encounter will lead Ryza to the key that will change her life forever—the creative and wonderful world of alchemy.

In Japan, betting on horse racing is one of the few legal forms of gambling; thus, the public races have become an interesting part of Japanese culture. In this sport, an individual who rides a horse and competes in races is called a jockey—that is just what Yuu Arimura aspires to be. Becoming inspired after witnessing a derby, 15-year-old idol Yuu shocks the entire nation when he leaves the entertainment industry to enroll in a prestigious horse racing school. Excited to pursue his latest passion, he gradually bonds with his new classmates—such as the talented Shun Kazanami and the self-assured Amane Grace—who are each unique in their own way. Although the path ahead may be full of obstacles, Yuu is determined to pursue his ultimate goal of becoming one with his horse.

Born from the strong emotions of their creators, self-contained pocket dimensions known as Phenomenon have begun forming across Japan. These false worlds overwrite the reality of an affected area and will only be undone if the maker is defeated or appeased. In response, a military-sponsored task force known as Trinary is formed, and its three members—Miyabi Koigasaki, Gabriela Lotaryńska, and Ayami Kunimasa—specialize in dispersing Phenomenon. Caught in one of these Phenomenon during her favorite idol's concert, Tsubame Ouse is saved by the timely arrival of Trinary, and together they are able to resolve the incident. After these events, Tsubame, along with newcomer Kagura Uzuki, decides to join the current Trinary team. As the girls struggle to balance their everyday lives and their responsibility to handle each new Phenomenon that appears, they realize that their own reality also has its own distinct set of problems.

Now branded for death and destined to be hunted by demons until the day he dies, Guts embarks on a journey to defy such a gruesome fate, as waves of beasts relentlessly pursue him. Steeling his resolve, he takes up the monstrous blade Dragonslayer and vows to exact vengeance on the one responsible, hunting down the very man he once looked up to and considered a friend. Along the way, he encounters some unlikely allies, such as a small elf named Puck, and Isidro, a young thief looking to learn swordsmanship from the former mercenary. As the ragtag group slowly comes together after having decided to join Guts in his quest, they will face incredible danger unlike anything they have ever experienced before.