[GundamAce]

Here's the "Prologue" section from Famitsu:

When he wakes up, he's in an elevator. Besides him is an unknown girl. However, it seems that she knows him. "Sigma... Why? Why does she know my name?" Sigma furiously draws near her, but his questioning is interrupted by a rabbit suddenly appearing on a monitor, telling them they have to escape the elevator quickly. Sigma and the mysterious girl, Phi, escape from the elevator, and before their eyes, they see a wide warehouse. Standing there is seven men and women they don't recognize. Sigma and the other eight must escape from this unknown place in a risky, treacherous game known as the "Ambidex Game". Faith and deception meet as they lie in fear of who will die first, as the curtain on the game known as "betrayal" opens up...