When the honmaru, watched over by the great Manyou cherry tree, is covered in pure white snow— The sword warriors Yamatonokami Yasusada and Kashuu Kiyomitsu are reminiscing about the past. It was when "Yamanbagiri Chougi," who claims to be the original song of the famed sword Yamanbagiri, was assigned to their honmaru by order of the Time Government. Yamanbagiri Chougi, who takes a provocative attitude toward his copy, Yamanbagiri Kunihiro, and Yamanbagiri Kunihiro, who harbors complex feelings toward him. Seeing the inner strength in Kashuu Kiyomitsu, who understands the feelings of these two swords and supports his comrades, Yamatonokami Yasusada makes a certain proposal to Kashuu Kiyomitsu.