In the 1590 Odawara Campaign, Maeda Toshiie led the northern army with Uesugi Kagekatsu and Sanada Masayuki, taking Hojo branch castles one after another. On June 23 he assaulted Hachioji Castle — left in the charge of subordinates while its lord Hojo Ujiteru was away at Odawara — with 15,000 men and overran it in a single day. The brutal fall, in which some 3,000 defenders and women perished, came to symbolize the collapse of Later Hojo rule in the Kanto.

Uesugi Kagekatsu formed Toyotomi's northern army with Maeda Toshiie and Sanada Masayuki, serving as a co-commander in the 1590 assault on Hachioji Castle. He helped take it in a single day and went on to the siege of Hachigata. His performance in this campaign contributed to his later elevation as one of Hideyoshi's Five Elders.

In 1590, the Siege of Odawara — the campaign Toyotomi Hideyoshi led as supreme commander to complete his unification of Japan — saw Hachioji Castle, a key Hojo stronghold, fall to forces under Maeda Toshiie and Uesugi Kagekatsu acting on Hideyoshi's orders, a defeat said to have shaken the Hojo troops besieged at Odawara Castle.