Hideki Sato, the successor of a mid-size chemistry company, is kidnapped by his father's secretary, Tsuyoshi Makiba (Ryo Fujimoto). Seeking revenge, the kidnapper demands the diamond "Florence no Namida", that got his mother killed, as a ransom, but, to his shock, Hideki’s father, CEO Zenichiro (Gaku Yamamoto),and his uncle, Vice President Yujiro, do not accept the demand. When Zenichiro succumbs to a disease, Yujiro uses this situation to start a plan to seize the company.