Based on novels by Miyuki Miyabe, Saburo Sugimura is employed in the public relations sections of Imada Corporation. When Sugimura receives an odd request from Yoshichika Imada, his father-in-law and the company chairman, Nobuo Kajita, the chairman's personal driver, ends up with tragic death. While Sugimura hopes the death was nothing more than an accident, new facts come to light with the possibility of foul play.