To prevent an outbreak, the military raid the quarantine zone and exterminate the infected with MOBA bomb, while the incident is covered up by the government.

Military intelligence forms a containment task force called GUIDE (Global United Infestation Detection and Elimination), recruiting operatives from around the world.

Four years later, a GUIDE ninja team, including the young Ken Ogawa and led by his father Kanbe, is dispatched to Tokyo to contain a massive Alpha-worm outbreak.

As Ken eliminates other major Alpha-worm Carriers, he is informed that the military are considering a mass sterilization of Tokyo via orbital laser cannon, which will sacrifice its entire population.

After thwarting an attempt to spread the infection overseas through a plane carrying evacuees, Ken learns that Kuroh has attacked the local shopping mall and rigged the Tokyo underground with explosive Carriers called Blast Mites.

The bombing, however, was meant as a distraction to allow Kuroh to lead a strike team of Carrier military operatives into the GUIDE headquarters.

Kanbe rescues Ken from a suicide attack by Kuroh, whereupon he confirms he volunteered to be infected, but only so that he could infiltrate and locate the Alpha-worm hive, which was buried underground to escape sterilization.

Ken defeats the core using the Ninja Blade and finally brings peace to his father, then the hive crumbles along with every trace of the infection.

The concept for Ninja Blade initially came when FromSoftware tried to create a game that conveyed the same intense sequences as those of Hollywood action films.

[13][14] Having signed a mutual publishing agreement with Noviy Disk, Iceberg Interactive released a retail version of the game in select regions in Europe on February 19, 2010.