Ōuchi clan
In 1551, Harukata succeeded in the coup against Ōuchi Yoshitaka, killing Sagara Taketō and leading Yoshitaka to commit suicide. The next year Harukata secured the control of the Ōuchi clan by making the adopted son of Yoshitaka, Ōuchi Yoshinaga (who was Ōtomo Haruhide, the half-brother of Ōtomo Sōrin), the head of the clan. At this time he changed his name from Takafusa to Harukata, as his master changed from Yoshitaka to Haruhide. Subsequently, he conducted a large military expansion, but this led to discontent among the retainers of the Ōuchi clan.