Buddies Back to Back is the twelfth episode of the Dr. Stone anime.


Senku must gather the most difficult material to obtain when compounding the cure-all drug: Sulfuric Acid. The Kingdom of Science discovers a pool of this material, and knowing the risks involved, Senku hatches a plan to obtain it.

Plot Details

As he promised Senku creates a silver spear using special plant roots. Happy, Ginro monologues and even taunts his brother. Kohaku shuts up him up while Senku explains they need it to get the maximum danger materials. They finish the silver spear and Senku reveals that Ginra must be the team's bodyguard.

Sulfuric Acid pool

The greatest hurdle to creating the cure-all drug.

Senku, Chrome, Kohaku, and Ginro walk past the hot springs and Senku reveals the silver spear is actually a sensor. If it turns black, that means danger is imminent and the holder must flee immediately or die. Senku says their opponent will kill them after just one mistake and this is the greatest hurdle to making sulfa drugs.

The group ends up at a river without a single fish and moves upstream from there. Ginro is too scared to fulfill his job as a bodyguard and walks far behind them. Senku and Kohaku make him walk ahead of them until they end up at a large pool of what appears to be an emerald green spring. Beautiful at first, Ginro walks toward it until his spear reacts to the hydrogen sulfide and turns back.

Senku yells at Ginro and Kohaku saves him in time before the gas kills him. This makes them all realize how deadly the spring actually is. Senku explains to everyone that the spring is made from Sulfuric Acid. They return to base and try to develop a plan to get the material. Kohaku wants to try and use her speed to quickly gather it, but Senku quickly debunks that, as people have been killed in an instant by the gas.

Senku and Chrome

Senku and Chrome put their lives in each other's hands.

To properly fight the chemicals, Senku gets Kaseki to craft gas masks. Senku tells Chrome that he can't come with him to get the acid. The gask masks aren't a guarantee and Senku says he can't let both of the scientists die. He wants to pass down all his knowledge to him, but Chrome outright refuses. He refuses to allow Senku to kill himself and promises to drag him back alive. They agree to raid the poison gas together after Chrome argues his point ad reveals to go together.

Kohaku recalls her father trying to get Ruri to pass down her knowledge to her. Their father had planned to make Kohaku her successor but she refuses to accept a plan that's okay with Ruri dying. In response, she decided to become unworthy of becoming priestess, determined to upset their father. Kohaku says she and Chrome are similar and asks if he'll marry her since Ruri will be taken. However, Chrome refuses and says Kohaku is nothing like Ruri.

Gas Masks

Gas Masks acquired!

Senku shows everyone how to make gas masks and the duo of scientists prepare to move out. They leave without the cowardly Ginro, taking his spear with them. He turns the sear back to silver and they return to the poison spring. They put their faith in the gas masks and try to act quickly. They can't freak out and waist their air, yet even Senku is slightly nervous.

Kaseki encourages Ginro to face his fears and embrace them because that's what keeps humans alive. No one is immune to fear, not even his brother Kinro. The old man gives Ginro the last gask mask and he's inspired to help save Rui despite his fear.

Sulfuric Acid acquired

The scientists and their bodyguard obtain Sulfuric Acid.

Meanwhile, disaster nearly strikes and Senku's gas line melts. Chrome warns Senku and he seals it, but the former falls toward the pool of acid. Senku runs after him but Ginro arrives in time to save Chrome from certain death. Chrome grabs on to Ginro's spear, but he's still to afraid to control his breathing and can't pull Chrome back to safety. Senku reassures him that they can win against nature if they use their hearts and mind.

Inspired, Ginro overcomes his fear and helps Chrome get back to a safe area. Together, the trio manages to obtain sulfuric acid.




  • Gas Mask

Anime to Manga Differences

  • A dialog mentioning about "hair-like things" is changed from Kohaku to Chrome.
  • When telling about the 100 Stories, there's no background images about the story in the anime.
  • There's no blunt faces of Kohaku and Chrome when they talk about marriage in the anime.


v  e
Arcs & Sagas
Prologue Saga
Stone Formula Arc
Chapters 1234
Episodes 12
Vs. Tsukasa Arc
Chapters 56789101112
Episodes 345
Ishigami Village Saga
Kingdom of Science Arc
Chapters 131415161718192021222324252627282930313233
Episodes 5678910111213
Village Games Arc
Chapters 34353637383940
Episodes 131415
Village Origins Arc
Chapters 4142434445
Episodes 1617
Stone Wars Saga
Vs. Hyoga Arc
Chapters 4647484950
Episodes 1819
Communications Arc
Chapters 5152535455565758596061626364656667686970717273747576777879808182
Episodes 2021222324
Source of the Petrification Saga
Age of Exploration Arc
Chapters 8384858687888990919293949596979899 100
Treasure Island Arc
Chapters 101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138
The Truth of the Petrification Saga
New America City Arc
Chapters 139140141142143144145146147148149150151152153154155156

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