오우치 씨
In 1551, Sue Takafusa revolted against his lord Ōuchi Yoshitaka in the Tainei-ji incident, forcing him to commit "seppuku". Takafusa changed his name to Harukata on this occasion and installed the next lord of the clan, Ōuchi Yoshinaga, but effectively led the Ōuchi clan and its armies, intent on military expansion. In 1554, Mōri Motonari became the leader of the Mori clan. As a vassal of the Ōuchi clan, he wanted to avenge the betrayed Yoshitaka, and so he rebelled against Sue, whose territorial ambitions were depleting clan resources.