"Sinbad: Mahō no Lamp to Ugoku Shima" is a prequel to the "Magi" series, focusing on the early adventures of Sinbad, a legendary figure destined to become a king. The story begins with Sinbad as a young boy living in the impoverished village of Parthevia. After his father, Badr, is unjustly executed by the Parthevian Empire for opposing their tyrannical rule, Sinbad vows to avenge him and bring prosperity to his homeland. His journey takes a pivotal turn when he encounters Yunan, a mysterious traveler who guides him to a dungeon, a mystical labyrinth filled with treasures and dangers.

Sinbad successfully conquers the dungeon, gaining the power of a Djinn, a supernatural being that grants him immense strength and magical abilities. This marks the beginning of his rise to prominence. Along the way, he forms alliances with various individuals, including Drakon, a loyal friend and future general, and Serendine, a princess with her own ambitions. Together, they navigate political intrigue, battles, and the challenges of leadership as Sinbad seeks to unite the world under his vision of peace and prosperity.

The narrative explores themes of ambition, friendship, and the moral complexities of power. Sinbad's charisma and strategic mind enable him to build a formidable crew and establish the foundation of his future kingdom, Sindria. However, his journey is not without conflict, as he faces adversaries like Barbarossa, a ruthless pirate king, and internal struggles over the ethical implications of his actions. The series delves into Sinbad's transformation from a vengeful youth to a visionary leader, setting the stage for his legendary status in the "Magi" universe.