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 joint 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.

[1]: 278 In 1584, Junkei fought in the Komaki Campaign against Tokugawa Ieyasu and after battle, his governance over Yamato was guaranteed by Toyotomi Hideyoshi.

The Tsutsui Clan subsequently lost governance of Yamato to Toyotomi Hidenaga, Hideyoshi's half-brother.