When the Mori clan became subordinate to Hideyoshi TOYOTOMI, who had seized power after the death of Nobunaga ODA, Hisasuke was ordered to participate in the project to unify the country, which was headed by Hideyoshi and fought on successive fronts across Kyushu.
織田信長の死後に権力を掌握した豊臣秀吉に毛利氏が従属すると、久扶も秀吉の天下統一事業に狩り出され、九州各地を転戦している。