Kenka no Gokui 6 (2010)

After fighting every single day, Haru and Shingo have grown absurdly strong.
Yet stronger enemies keep coming—this time from Byakuya Academy, whose elite unit “Brother Scorpion” launches a full-scale assault.
Overwhelmed by numbers, Kiwakō faces its greatest crisis.
Momo entrusts everything to Haru, marking a generational shift as the ultimate school war begins.
In the chaos of battle, Haru is forced to discover what strength truly means.