The time has come to test the power of the Nanban weapons. The young Kobayakawa Chikaharu, accompanied by the finest samurai the Otomo had to offer and many Ashigaru spearmen, marches from the encampment into the rice farms of the Shimazu. The Portuguese, eager to prove the value of their trade, send 180 men of their own, along with the samurai who had learned the art of the gun and the few peasants who had taken but a few lessons. The lack of archers and cavalry failed to concern Chikaharu, for with the strength of firearms, who could oppose him?
The Shimazu general, a man of meager talent, commands a host of peasants accompanied with archers, but the talented Shimazu samurai, armed with spear and sword, more than made up for the lack of bravery in the hearts of the common men. Eager for a fight, the Shimazu charge across the rice fields into the range of the Otomo gunmen. The Portuguese fire first, their volley striking true. Many samurai fall, but still the Shimazu swordsmen charge, covered by the volley of their archers whose range the Otomo cannot match. The gunmen can only fire two volleys before the Shimazu close the gap, with a melee ensuing across the line. The Otomo spearmen move forward, their line of pikes held steady. The large number of fresh troops now cutting through their forces scares the Shimazu away after ten minutes of bloody struggle.
With their line breaking, the samurai of Osumi, their spears unequaled by anyone on the island of Kyushu, began a desperate charge into the left flank of the Otomo. They pray that the deaths of the Portuguese gunmen will scare the mostly peasant army of Chikaharu. But their plan is foiled by the arrival of Momochi Yasunaga, the aspiring officer whose valor in the Battle of Saito had earned him much honor, and his contingent of samurai. The action is short lived; the Shimazu are routed, leaving only the archers between the confident Otomo forces and the fleeing Shimazu.
But overconfidence can ruin a man. With his army pursuing the fleeing forces, Chikaharu orders his bodyguard to destroy the archers that have spent the entire battle picking off his gunmen. The original charge is successful, but soon his cavalry is surrounded by spearmen who have regained their courage. Soon his own courage is lost, and he abandons his men to unfulfilling deaths or worse. As he flees the field, the Otomo curse their luck and fortune, and wonder aloud how such a victory could be ruined in but an instant.
It is here that Yasunaga shouted at his samurai unit, and word spread that the battle lines were to be reformed. The Shimazi, encouraged by their general who had yet to approach the fray, Reform their lines as well. Again the Shimazu charge the Otomo gunmen, and again the Otomo spearmen meet the opposing infantry. The words of Yasunaga lift the Otomo spirits, and at last the Shimazu general is forced to fight. Just as Chikaharu had been defeated by peasant spears, so too is his opposite number, but his escape route is cut off and his horse cut out from under him, his broken body trampled underfoot as his army is thoroughly routed from the field.
The Otomo, although bloodied, had learned much from this fight. The gunmen had proved their worth, and gained experience with their weaponry as well. The legend of Momochi Yasunaga continued to grow as the honor of Kobayakawa Chikaharu was furthered diminished. Only time would tell how the members of the Otomo clan would use the new found knowledge...