Kaname Chidori's one of the most popular girls at her high school - unfortunately, it's her growing popularity off campus she should be worrying about. Unbeknownst to Kaname, terrorists are plotting her abduction. That's where Sousuke Sagara enters the picture. He's a hotshot soldier from the clandestine counter-terrorist organization known as Mithril - and he's going undercover at Kaname's school to try and keep her safe.

Kaname Chidori's one of the most popular girls at her high school - unfortunately, it's her growing popularity off campus she should be worrying about. Unbeknownst to Kaname, terrorists are plotting her abduction. That's where Sousuke Sagara enters the picture. He's a hotshot soldier from the clandestine counter-terrorist organization known as Mithril - and he's going undercover at Kaname's school to try and keep her safe.

Soon after the Tuatha de Danaan's hijacking, Sousuke comes to the rescue of Kurz and Mao, who have infiltrated a Mafioso's mansion to track down the traitor responsible for putting the Tuatha de Danaan in danger. After being chased by Mafia thugs and three Arm Slaves, an unknown and technologically advanced AS appears. But who is piloting the black AS? Is it an enemy or an ally? What is the surprising truth that is about to make itself known to Sousuke and company?

It's tough to keep your grades up without having to take off at a moment's notice to save the world. But for Sousuke Sagara, undercover high school student and member of the mercenary group Mithril, life in Tokyo seemed the same as always. But underneath the promising exterior spin the wheels of a conspiracy that threaten to destroy the peace. A new threat has arisen: Amalgam.

Tensions are at an all-time high as the world spins rapidly out of control. Kaname is left alone when Sousuke disappears from class, and this time he seems to be gone for good. The spunky Whispered may be a survivor, but just how much can one high school girl survive?

As the Chinese conflict rages on, hostilities reach a fever pitch. The final countdown hastens near. The SRT offensive is launched, but Sousuke has abandoned his post. Cryptic messages from a bloody past lead the young mercenary to face his demons, the battle within no less than the one without. Life and death hang in the balance as the clash between good and evil scale new heights. Piloting the Arbalest into the dawn, the last act is set to begin.