Yamano Dodai was an Imperial Japanese Navy sailor who served in World War II. A map containing a blueprint of the Iwami Shipbuilding base in Onomichi was hidden in his grave by the Saio Triad so that the "Secret of Onomichi" could be revealed someday, and Kazuma Kiryu and his friends from the Hirose-gumi discovered the map at Dodai's grave after decoding a Saio message leading them there.