re: Shogun - Official Series Discussion Thread **Spoilers**

There is an emperor in Japan during the events of the series and the historical events its based on, but it is not the boy. In that era, the emperor is purely a deity like figurehead and is isolated from any real power by the daimyos.

In the series, Toranaga refers to the emperor at least once when he says something along the lines of "we all honor his imminence in Kyoto." Also, Taiko isnt a hereditary position, but the Taiko was able to unify the daimyos enough to agree to preserve the peace by allowing his son (the boy) to take power, and he tried to ensure that setup by creating the council of regents.