The story takes place on Gaia, where magic is viewed by many as a taint. Many years before the Great War, a prophecy was told "The fabric of time, its guiding forces, and the world they govern will fall into disarray. The Chaos Complex, born to a daughter Sram and a son of Gaia, will be the edge to tear the fabric. Its hope, fear, and courage will find their place in this world."
The menu screen gives you access to many aspects of your characters, including skills and equipment. It also contains a codex that explains the terminology and concepts of the game and its systems.