Takagi Fujimaru may seem like a regular high school student, but behind the cheery facade lies a genius hacker by the name of Falcon. When his father is framed for a murder, Falcon uses his brilliant hacking skills to try and protect his sister and clear his father's name. However, he finds that his father, an agent in an elite government agency, was involved with something far more complex than a simple murder. A terrorist group is plotting against the city of Tokyo and it is up to Falcon, with the help of his friends, to unravel the twisted plans set in place to kill millions of people.
In the incident at the purification plant, religion founder Shimon Kamijima died, and J went missing. It seems as if the threat of terrorism is over. But a new leader named K, unknown to THIRD-i, was planning another terrorist attack underground. Can Fujimaru uncover the identity of the terrifying K and the true meaning of “Bloody Monday”?