Konishi Yukinaga
Yoshitoshi was the fifth son of Sō Masamori; his wife, who took the baptismal name Maria, was the daughter of Konishi Yukinaga. Yoshitoshi became the head of the family in 1580, after his adoptive father, Sō Yoshishige, was defeated, and Tsushima conquered, in a prelude to Toyotomi Hideyoshi's Kyūshū Campaign.