Kumogakure's ultimatum crashed like a thunderclap, shattering Konoha's brief calm. Though Hashirama Senju strongly advocated further negotiations to uncover the truth, pressure from Tobirama Senju and the Hawks he led, along with the village's mounting appetite for war, ultimately drove the Konoha High Command to reinforce the border and respond forcefully to the Cloud Village's threat.
The clouds of war instantly descended over the Land of Fire's border.
The Uchiha Clan, the main force of the newly established Konoha Police Force, had originally been deliberately excluded from the regular mission system by Tobirama. But with an external war imminent, especially when the Sharingan's insight was needed to counter Kumogakure's elusive Lightning Style ninjutsu and stealth tactics, Uchiha strength became indispensable.
Thus, a border emergency unit made up of shinobi from several different clans was quickly assembled, including several Uchiha Jonin and Chunin. Uchiha Sou, with his cool head and combat skills honed back in the Warring States Period, was naturally among them.
Sou wasn't surprised. This was both a crisis and the opportunity he had been waiting for. Far from the village center, amid the chaos of the war zone, he might be able to track signs of Black Zetsu's possible activities more clearly—and find a better chance to... acquire the Mangekyō Sharingan in the future.
Several days later, in the sprawling mountain range along the border between the Land of Fire and the Land of Lightning.
The terrain here was steep and shrouded in mist. Vast ravines and dense primeval forests formed a natural battlefield, making the area ideal for small units from both sides to infiltrate, conduct reconnaissance and counter-reconnaissance, and engage in small-scale skirmishes.
The air was filled with the smell of damp earth, rotting vegetation, and the faint scent of ozone left behind by Lightning Style