Black Rock Shooter: Fragment

In the 22nd century, humanity has established a global network that manages the world's public transport, factories, power plants, personal devices, and everything that makes the world go round. However, the network eventually gives birth (possibly by accident) to an A.I. entity called Innocent Cloud, which proceeds to take over the network, following it up with an attack on humanity by using a virus. In response, a team of warriors immune to the virus, nicknamed Synthetics, are developed to fight back against Innocent Cloud. The struggle proves to be a long-term stalemate, however, partially due to humanity having lost all their advanced technology to Innocent Cloud and having no means of contacting each other over long distances. This also means that they struggle to trust the Synthetics that were sworn to protect them.