Final answer:
The Tokugawa shogunate held the most power under Japanese feudalism, with the shogun acting as the military leader and ultimate authority.
Step-by-step explanation:
The person who held the most power under Japanese feudalism was the Tokugawa shogunate. The shogunate was led by the Tokugawa family, starting with Tokugawa Ieyasu who took control of Japan in 1603. They continued to rule Japan for over 200 years, establishing a strict hierarchy and centralizing power in the hands of the shogun, who acted as the military leader and held ultimate authority. The daimyos, or feudal lords, also had significant power within their territories but were subject to the control and regulations imposed by the shogunate.