As war broke out in the Land of Rain and the Land of Rivers in succession, fierce fighting also erupted in the Land of Grass Territory. With the shift in strategic priorities, the main enemy force in the Land of Grass was now the Iwagakure Ninja Village. Facing pressure from both Konoha Ninja and Kumogakure Ninja, the Iwagakure Ninja displayed astonishing tenacity.
After Kazemori Masaki arrived, morale soared among the Konoha Ninja. Eager to prove themselves before the Hokage, they launched unexpectedly fierce attacks against the Iwagakure Ninja. Their use of Explosive Cannons grew increasingly refined, and once the Lightning Explosive Tag series of ninja tools arrived, their ability to suppress the Iwagakure Ninja became even greater.
Rock walls that had once needed repeated bombardment to bring down proved far less formidable against the explosive power of Lightning Explosive Tags. Mines made with Lightning Explosive Tags could also be buried deeper than Explosive Tag mines and proved more effective, completely blocking the Iwagakure Ninja's attempts to infiltrate along the ground.
Of course, the Iwagakure Ninja were not entirely set in their ways. After discovering that rock walls offered little protection against Explosive Cannon bombardment, they changed their tactics, focusing on reshaping the terrain and building trenches to defend against the shelling.
Indeed, after changing their defensive approach, the Iwagakure Ninja became noticeably better at weathering Explosive Cannon fire. Without towering rock walls blocking their sight, they also had more time to react to Konoha Ninja sneaking closer under cover of the bombardment, dragging the battle out even longer.
In response, Konoha Ninja Village promptly adjusted its bombardment methods, firing its "shells" along Parabola-shaped trajectories. The village had long since begun teaching the mathematics needed to calculate those trajectories. The mathematical calculations that had seemed like nothing more than baffling questions