In the medieval kingdom of Pars, young Prince Arslan faces his father's hostility and his mother's indifference, while longing to learn more about the world. Despite being surrounded by poverty and slavery, Arslan continues to see the possibility of a nobler world. Everything changes when the neighboring nation of Lusitania invades Pars, forcing Arslan to grow up in an instant. Arslan Senki follows Prince Arslan into war, where he struggles to save his nation and family with the help of a small but devoted circle of advisers. Along the way, the young prince discovers secrets around every corner and faces enemies who hate him because of what he is, but also finds friends where he least expects them. The story of nations at war, Arslan Senki is also the story of one boy's quest to stay himself in the most trying of circumstances.