After first serving Niwa Nagahide as a page, Ueda Sōko was later chosen by Toyotomi Hideyoshi as one of his aides and daimyo.
Following the Siege of Osaka (1614-1615), the Toyotomi clan was disbanded in 1619 and Ueda relocated to Hiroshima under his lord Asano Nagaakira who was to become Daimyo of the Geishū domain (Hiroshima domain).