A nuclear facility in Japan falls victim to a terrorist attack, and the sole clue left behind is the word "VON" in red paint. Governance is thrown into chaos, and an all-out search for suspects ensues. Much later, a video surfaces online featuring two individuals donning Sphinx masks and identifying themselves as two teenagers threatening Tokyo. The resulting pandemonium is uncontrollable by the local police, and Detective Kenjirou Shibazaki is left with the task of investigating and bringing the terrorists to justice. "Zankyou no Terror" is centered around the story of Nine and Twelve, two boys who adopt the mantle of Sphinx to wreak havoc and conceal their tragic past in a world of deceit and machination.