豐後國
As Shigetane was additionally known by the name of 'Takahashi Shoun' during the earlier years of his life, he began his service beneath the Ōtomo of Bungo Province around this same initial time, with Ōtomo Sōrin as their leader and head. Eventually, Shigetane became the respective controller of the Takahashi clan, in which he was additionally regarded as one "Great Pillars" of power to the Otomo clan, being granted Iwaya Castle that bordered Chikuzen Province in contribution to his authority and prestige.