The feudal lord of the Matsukura clan in Oshu was an enthusiastic collector of famous swords. He was eager to acquire two of the most famous swords in the world, Magoroku of Seki, and two swords, Kengun and Kunryu, large and small. Eizaburo Suwa, one of his retainers and the best swordsman in the clan, was ordered to acquire these two swords even if it cost his life.