Souma Tooru, once a fearless hacker, is forced to join the ranks of FLAK. Indentured into service and out for revenge, the young man reflects on the dead of the past as a ghost takes shape in the present.

A joint exercise between VSS and FLAK goes horribly wrong. Tooru's hunt for Yuuya's killer is interrupted by an encounter with a strange little girl named Ren.

Tooru's life is in chaos after the discovery of who killed his best friend and the sudden disbanding of his platoon. Complicating matters, strange Ren has become the target of a furious manhunt.