Senku and Taiju prepare to make Yuzuriha as the first person they revive with their completed water, only to suddenly be chased by lions. In order to fight them off, the duo decide to instead revive the strongest fighter in their school, Tsukasa Shishio, who proves to be a valuable hunter. As the group begin harvesting seashells to grind into calcium carbonate for further advances in civilization, Tsukasa, who is against reviving the corrupt adults of human society, clashes with Senku, who remains determined to save everyone.

The group embarks on a hunt for gunpowder making supplies; an accidental explosion leads to a fight.