Date Masamune was a regional ruler of Japan's Azuchi–Momoyama period through early Edo period. Heir to a long line of powerful daimyō in the Tōhoku region, he went on to found the modern-day city of Sendai. An outstanding tactician, he was made all the more iconic for his missing eye, as Masamune was often called dokuganryū (独眼竜), or the "One-Eyed Dragon of Ōshū". As a legendary warrior and leader, Masamune is a character in a number of Japanese period dramas.

The third Siege of Odawara occurred in 1590, and was the primary action in Toyotomi Hideyoshi's campaign to eliminate the Hōjō clan as a threat to his power. The months leading up to it saw hasty but major improvements in the defense of the castle, as Hideyoshi's intentions became clear. Thus, despite the overwhelming force brought to bear by Hideyoshi, the siege saw little actual fighting.