A coup by the military establishment of Japan's Ōuchi clan forces their lord to commit suicide, and their city is burned.

The Tainei-ji incident was a coup d'etat in September 1551 led by Sue Takafusa against Ōuchi Yoshitaka, hegemon and shugo daimyō of western Japan, which ended in the latter's forced suicide in Tainei-ji, a temple in Nagato Province. The coup put an abrupt end to the prosperity of the Ōuchi clan, though they ruled western Japan in name for another six years under the figurehead Ōuchi Yoshinaga, who was not related to the Ōuchi by blood.