The game takes place in a world where humans and monsters coexist, and the story follows a young protagonist, a Rider, who embarks on a journey to become a legendary Monster Hunter. The world is threatened by a catastrophic event known as the "Demonization," which causes some monsters to become corrupted and wreak havoc on the land. As a Rider, you must explore the world, befriend monsters, and uncover the truth behind the Demonization.