Dr Stone Vol 4

Imagine waking to a world where every last human has been mysteriously turned to stone...
One fateful day, all of humanity turned to stone. Many millennia later, Taiju frees himself from the petrification and finds himself surrounded by statues. The situation looks grim - until he runs into his science-loving friend Senku! Together they plan to restart civilization with the power of science!
Senku and friends make their way through the scientific road map that'll lead them to the Ruri's cure! Next up, a death-defying quest to obtain one of the deadliest substances on Earth - sulfuric acid! Meanwhile, the Grand Bout Martial Arts Tournament approaches, and the prize is a big one - the chief's throne!