Early in his career, in 1565,
Matsunaga Hisahide, one of the most powerful warriors of the region, defeated Junkei and took Tsutsui Castle, but one year later in 1566, Junkei's Tsutsui castle was reclaimed after the battle against Hisahide, but shortly afterward he had to abandon it, following an order by Nobunaga. In 1575, he joined the attack against the
Echizen Ikkō-ikki, he participated in a unit among the forces from
Yamato led by
Harada Naomasa. In 1577, by joining the forces of
Oda Nobutada, along with
Akechi Mitsuhide and
Hosokawa Fujitaka, Junkei defeated Hisahide in
Siege of Shigisan at
Mount Shigi. In 1578, He was then appointed to the position of
daimyō over Yamato, and was allowed to build a new castle, which was called
Kōriyama Castle, now in
Yamatokōriyama, Nara. He participated in the
Siege of Itami (1579) against
Araki Murashige and
Tenshō Iga War in the
Siege of Hijiyama in (1581) against forces of
Iga Sōkoku Ikki. In 1582, during the
Battle of Yamazaki, Junkei refused to take either side and remained neutral awaiting the results of the battle at "Hora ga toge". This is the origin of the expression, "To sit on Hora ga toge", when referring to indecision. In 1584, Junkei fought in the
Komaki Campaign against
Tokugawa Ieyasu and after battle, his governance over Yamato was guaranteed by
Toyotomi Hideyoshi. ==Death==