Yokenji was founded in 1609 by Mori Takatomo, first lord of the Saiki domain, who had served Toyotomi Hideyoshi. After Hideyoshi's death, Takatomo emerged from the Battle of Sekigahara with a grant of 50,000 koku at Saiki, and built this Soto Zen temple as the Mori clan's mortuary temple. It endures as a trace of the feudal order Hideyoshi's retainers planted across Japan.