In the rural territory of the Ristia Kingdom, there lived a lower-ranking noble family, the Oernstein family. Within this household, there were two siblings.
The older sister, Marie, was an energetic girl who loved receiving swordsmanship lessons from her father. The younger brother, Shion, was a shy boy who loved to lock himself in his room and read books.
Though their personalities were completely opposite, the two siblings lived harmoniously under the watchful eyes of their kind parents.
One day, Shion asks his father whether "magic" exists in this world. However, even his well-educated father, who is a noble, had never heard the term "magic." Moreover, the phenomena Shion described—"things like fire, water, wind, light, and pulling various things out of nowhere"—seemed impossible in their world.
From that day on, Shion became visibly downcast.
Wanting to cheer him up, Marie confides in her childhood friend, Rose, the daughter of a farmer. Then, they witness a mysterious phenomenon by the lake...