"Aoi Sekai no Chūshin de" is set in a fantasy world where two dominant nations, the Kingdom of Consume and the Empire of Sega, are locked in a prolonged war. The conflict stems from their differing ideologies and the desire to control the world's resources. The Kingdom of Consume, led by King Teol, is a technologically advanced society, while the Empire of Sega, ruled by Emperor Zail, relies on mystical and magical forces. The war has devastated the land, leaving its inhabitants desperate for peace.

The protagonist, Gear, is a young warrior from the Kingdom of Consume who wields the legendary sword, Falchion. Gear is determined to end the war and bring stability to the world. Alongside him is his childhood friend, Niko, a skilled archer who shares his ideals. Together, they embark on a journey to unite the fractured nations and confront the forces perpetuating the conflict. Their mission is complicated by the presence of powerful adversaries, including the enigmatic warrior, Segua, who serves the Empire of Sega and possesses immense strength and strategic prowess.

As Gear and Niko traverse the war-torn world, they encounter various factions and individuals, each with their own motivations and allegiances. The narrative explores themes of loyalty, sacrifice, and the consequences of war, as the characters grapple with their roles in shaping the future. The story also delves into the origins of the conflict, revealing deeper layers of political intrigue and ancient prophecies that tie the fates of the two nations together.

The series blends action, adventure, and elements of political drama, with battles that showcase the contrasting strengths of Consume's technology and Sega's magic. The characters' development is intertwined with their struggles against external threats and internal doubts, creating a dynamic and engaging narrative. The resolution of the story hinges on Gear's ability to reconcile the differences between the two nations and forge a path toward peace, challenging the entrenched ideologies that have fueled the war for generations.