Hitoshi Tadano is an assistant manager of an advertisement company who seems to be nothing but a dull and incapable “nobody”. While most of the employees wonder why such a passive and incompetent person like Hitoshi is yet to be laid off, there is just one person who heavily relies on him as a “savior” to the company, the CEO. In fact, the “Mr. Nobody” is simply a disguise from the real Hitoshi, as he is under various special missions of the CEO to quietly carry on his “extraordinary” task to fight against the corruption of the company.

Tadano is assigned by the chairman Kurokawa to protect and check the personal affairs of a young idol, Sylvia , who is the main character at the "Flower Earth Festival 2008" organized by Denodo. Sylvia has been threatened by someone to resign from the main character role. Tadano starts investigating while supporting Yamanishi, the event organizer. However, Tadano is struck down by a mysterious giant of a man. Yamanishi, who has obtained important information, is murdered, and Sylvia is kidnapped. Tadano realizes that Anzai, Yamanishi's right-hand man who has been eyeing the chairmanship, is the mastermind behind this. Tadano rescues Sylvia and brings her to the event venue.