Amago Takahisa was a family member of the Amago clan of Izumo Province.  Takahisa was the third son of Amago Kunihisa, the lead commander of the shingūtō, an elite fighting force of the Amago.  As a member of the shingūtō, Takahisa joined his father and older brothers in assorted battles.  In 1540, he participated in the Battle of Yoshida-Kōriyama and lost.  In the summer of 1544, Takahisa served in the main contingent of soldiers to invade Bingo Province.   In a clash known as the Funo kuzure, the Amago attacked Miyoshi Hirotaka at Hiebiyama Castle in Bingo.  In addition to the Miyoshi, the defenders included soldiers from the Mōri, both of which were serving the Ōuchi.  The Amago forces initially defeated the defenders, but the following day, the Miyoshi caught the Amago off-guard with a surprise attack, and defeated them.

Despite their military prowess, the ferocity and arrogance shown by members of the shingūtō led Amago Haruhisa, lord of the Amago clan, to view them as a threat.  The disrespectful behavior of Sanehisa and Takahisa also affected relationships with other members of the group, including discord between Takahisa and Sanehisa’s son, Amago Ujihisa.  In 1554, following the death of Takahisa’s sister, who was Haruhisa’s formal wife, Haruhisa decided to purge the members of the shingūtō.  Kunihisa was killed departing the castle, while other members were attacked in their quarters.  Takahisa took his own life on the day after the raid.