Hidenobu Kiuchi

As the world moves on from the war and technological advances bring changes to her life, Violet still hopes to see her lost commanding officer again.

In a post-war alternative timeline, Japan is divided into the North, controlled by the Union, and the South, controlled by the United States. A mysterious high tower rises within the borders of the Union. Three high school students promise to cross the border with a self-built airplane and unravel the secret of the tower.