Shinobi World Corporation is a household-name Japanese trading conglomerate that operates in food, energy, chemicals, and logistics. Behind the glass towers and polished suits, however, it is the oldest surviving intelligence agency in the country: a ninja organization that has protected Japan from the shadows for centuries. The company’s employees are trained operatives who handle everything from corporate negotiations to assassinations, all while maintaining the appearance of ordinary salarymen.

The story centers on Hattori Shozo, the silver-haired head of the sales division. To his colleagues and clients, he is a clumsy, mediocre salesman whose presentations are embarrassingly bad and whose sales record is unremarkable. In truth, he is the company’s chief ninja, a master of combat and espionage who earned his rank in just five years. When a new recruit, Sasaki Kotaro, joins the department, he is secretly a government spy sent by the Chief Cabinet Secretary to investigate Shinobi World’s suspicious activities. Sasaki soon witnesses Hattori single-handedly slaughter a squad of Chinese infiltrators in the office hallway, revealing the true nature of the company. The government ultimately agrees to look the other way, and Sasaki becomes a reluctant insider.

The narrative follows the daily grind of ninja-salarymen: business meetings that double as cover for covert operations, after-work drinking sessions where colleagues discuss realpolitik and personal trauma, and the constant threat of foreign agents. Hattori’s past is tied to his mother’s murder by the KGB, which drove him to begin ninja training at age six. As the series progresses, the company faces a double crisis: its corporate structure has become rigid and outdated, and Russia’s growing influence in East Asia puts Japan at risk. Worse, Hattori’s father, the company president Hattori Hanzo, disappears under mysterious circumstances. Forced to step up, Hattori must navigate internal power struggles and external military threats while trying to reform the organization from within. The story builds to a conclusion where he confronts the forces seeking to destroy Shinobi World—both from rival nations and from within its own boardroom—and ultimately decides the future of the centuries-old institution.