Two Nations of the Stone World (石の世界の二つの国 Ishi no Sekai no Futatsu no Kuni) is the sixth episode of the Dr. Stone anime.
The flashback to Senku's awakening continues. With his basic necessities met, he recognizes that he needs additional manpower to continue progressing science. He finds Taiju's statue and attempts to revive him using the nitric acid from the Cave of Miracles nearby. He deduces that depetrification must require some additional factor. For him, it was that he maintained consciousness during his petrification. He begins experimentation to see if another method of depetrification exists. (This leads into the events of Episode 1.)
In the present, Senku is revived with the help of the Stone Formula. He decides to split up from Taiju and Yuzuriha in order to build a "Kingdom of Science" to fight against Tsukasa. The other two will serve as spies within Tsukasa's empire.
Meanwhile, Kohaku confronts Tsukasa for attacking Senku and Yuzuriha. Tsukasa traps Kohaku under a tree and flees after determining that securing the Cave of Miracles is his top priority. Senku arrives, creating a system of pulleys to lift the tree, rescuing Kohaku.
Following a long day in the new Stone World, Senku has his basic necessities met, but he requires additional manpower to progress further. Senku finds and dig sup Taiju's statue and tests nitric acid on him.
When the nitric acid is initially ineffective on Taiju, Senku deduces the depetrification must require some additional factor. He tries and tests everything that comes across his brain until he finally realizes staying awake for those centuries allowed him to break out of the stone. Senku continues to experiment until eventually, Taiju awakens.
Back in the present day, Taiju calls for Senku to awaken in the same way Senku did for him that short while ago. Senku suddenly awakens and is embraced by his friends. Unfortunately, their time together is short and they decide that Taiju and Yuzuriha will spy on Tsukasa's new empire while Senku leaves to build a "Kingdom of Science".
A newcomer confronts Tsukasa in the mountains. He realizes that she is of a generation far after the humans that were petrified. She witnessed Tsukasa attack Senku and the others. Despite her considerable skill, Kohaku is overpowered and trapped beneath a tree by Tsukasa. His top priority is securing the revival fluid, so Tsukasa leaves her behind to get back to the cave before Taiju and Yuzuriha.
Senku eventually happens upon Kohaku and asks her if he wants him to blow up the tree quickly or take his time. Senku promises to free her with time, so Kohaku agrees to wait beneath the tree. After several hours, Senku creates a system of pulleys that lifts the tree gently off the girl. Amazed, Kohaku admits she's taken a liking to Senku the "sorcerer".
- Kohaku vs. Tsukasa
Anime to Manga Differences
- A panel showing Senku has a shock in the backbone is omitted in the anime.
- There is an additional scene showing Senku and Taiju calling each other's name before Senku wakes up.
- The anime version shows Kohaku and other real characters instead of random primitive characters in Senku's imagination.