In episode 17, Asagiri Gen told Senku that the Kingdom of Might was on their way. They didn’t waste any time, because moments after Senku received the news, Ginro and Kinro were attacked at the bridge. Kinro attempted to hold the Kingdom of Might soldiers off but due to his fuzzy sickness, he was unsuccessful. He gave Ginro instructions to alert the rest of the village and cut the bridge if things got bad.
The leader of the Kingdom of Might soldiers, Hyoga-chan. He is a skilled spear used sent by Shishio as his right hand. His group catches Kinro and Ginro off guard and as a result Kinro sustains a wound to the stomach and is forced off of the bridge.
As Kinro dangled from the bridge, he calls out to Ginro to cut the line and save the village. However, Ginro could not come to terms with killing his brother to try and save the village so he refused. Luckily, Senku arrives and comes up with a plan.
Senku manufactured a smoke bomb to trick the Kingdom of Might into thinking he has guns. Magma throws a rock simultaneously to enhance the illusion. Hyoga and his group retreat and luckily Kinro is still alive. Senku treats Kinro and he begins his road to recovery. Senku also gives him glasses to help with his fuzzy sickness.
Unfortunately, Senku knows that Hyoga will be back because his identity has been revealed. Senku determines that the Kingdom of Might will be back under the cover of the rainstorm. With that in mind, the Kingdom of Science works hard to prepare for them before the storm comes.
When the Kingdom of Might attacks, the Kingdom of Science meets them on the bridge with katanas to fight back. Kaseki had created the katana with the help of Senku and the others.
Asagiri Gen tells Hyoga that Kohaku, Kinro, and Magma are the strongest in the village. Kinro realizes that Gen is indirectly telling them that all three of them will be needed to defeat Hyoga.
Hyoga engages in a fight with the group and twirls his spear around until the spear snaps off of its handle. It turns out the Asagiri Gen sabotaged the spear after the Kingdom of Might initially attacked. Hyoga figures out that he’s been double-crossed and Asagiri Gen is forced to explain his actions while officially taking his place next to Senku in the Kingdom of Science.