Shima Sakon was a brave and honorable samurai, and grandfather of Yagyu Yoshikane (Yagyu Renyasai). He was a capable subordinate of Ishida Mitsunari, and fought against Tokugawa Ieyasu in the battle of Sekigahara. Some history books tell us Sakon had died in that battle. Others say he survived and escaped to Kyoto with the Yagyu family. And others…?

During the feudal era, warlords were not only in danger from enemies outside the castle, but also from within like their own lieutenants they trusted. To protect themselves, they secretly began to use decoys of themselves. Honda Masanobu was part of Tokugawa Ieyasu’s council and also his closest friend. However, to defend his home country from Oda Nobunaga’s campaign, he leaves his position. During the 10 years on the battlefield, he meets Jirosaburo Motonobu who looks almost identical to his former master. Masanobu comes to realize that Jirosaburo must become Ieyasu’s shadow because of his trustworthy character and battle experience. But when Ieyasu is murdered by a ninja right before the most important battle of his career, Jirosaburo must hide the truth and assume the identity of Ieyasu, for the sake of the Tokugawa clan!

Tokugawa Iemitsu struggles with his fear of death and finds salvation in the young samurai Samon of the Yagyû clan. But their relationship triggers a battle for power and respect, stirring tension between the Shogun and the Yagyû clan. In five chapters, the story depicts each of the main characters and follows their downfall as the plot unfolds.