Page "Emperor Yōzei" Paragraph 9

According to very scanty information from the Imperial archives, including sources such as Rikkokushi, and Nihon Sandai Jitsuroku, Emperor Yōzei murdered one of his retainers, an action that caused massive scandal in the Heian court.

Japanese society during the Heian era was very sensitive to issues of " pollution ," both spiritual and personal.

Deaths ( especially killing animals or people ) were the worst acts of pollution possible, and warranted days of seclusion in order to purify oneself.

Since the Emperor was seen as a divine figure and linked to the deities, pollution of such extreme degree committed by the highest source was seen as extremely ruinous.

Many of the high court officials construed Emperor Yōzei's actions as exceeding the bounds of acceptable behavior, and as justifiable cause for the emperor to be forcibly deposed.