Chaseten Bartels’s Reviews > Dr.STONE 6 > Status Update

Senku's father, Byakuya, returns to Earth after humanity has been petrified. Meanwhile, Senku and his friends are attacked by assassins from the Tsukasa Empire. In the midst of this emergency, they begin developing the ultimate weapon, the "Blade of Science," to protect the village. The Katana is what was made. They made it by folding steel over and over, then sharpening it.