During the Meiji restoration, The city ofAizuwakamatzu was the last in Japan to westernize. In fact, They resisted, and the Byakkotai helped to defend against the intruding Shogun's who were forcing westernization on all of Japan.
They retreated to the nearby Iimoriyama hill, and Looked out over the valley. Upon seeing the Castle Burning, they commited suicide, or Jisatsu, because they felt they had dishonored their Shogun. So strict is the bushido code.
In Actuality, only the town around the Castle was burned. After the Fires subsided, the castle was still standing.
One boy, Sadakichi Iinuma, survived and so the details of the story were recorded