Stone Road (
Summary
The quest to develop antibiotics begins! Senku Ishigami draws up the road towards their development, opting to create a sulfa drug with certainty rather than a penicillin by chance. The first step is obtaining iron.
After Senku realizes that the Earth's rotation has shifted since the Petrification, Chrome shares a piece of magnetic iron he'd acquired, which they then use to gather iron sand from a nearby river. Suika appears, joining the group in their mission.
To manufacture iron from iron sand, the group needs an oven that can reach 1500°C. However, their current manpower isn't enough to bring a fire to that temperature.
Aiming to recruit villagers to his side, Senku has Suika investigate. They determine that the best course of action is to cook up delicious food. Together, the group makes foxtail ramen, which, although bland to Senku, is revolutionary to the villagers. Senku, Chrome, and Suika set up shop outside the village, hoping to secure new allies.
Plot Details
The people of the village question where this mysterious stranger could have come from. Kokuyo, father of Kohaku and Ruri, asks if his youngest daughter brought the stranger. Jasper tries to cover for her, but Turquoise reveals it was Kohaku who broke the rules. Ruri notices her father's rage and falls to the floor from her sickness.

Just outside the village, Chrome and Kohaku get pumped about working with Senku to cure Ruri. Senku plans to cure Ruri and win over the village by creating the antibiotic. He explains that they can take the biological route by making penicillin or go the stone route and create sulfa drugs from rocks.
Confused, Kohaku asks how they can make medicine from those things. Senku replies that making penicillin from moss is the more famous route, but it's too risky. Chrome agrees they should go the stone route because Senku knows it can work with the right amount of manpower. Senku shows them both the roadmap that will allow them to skip two million years straight to the cure-all drug.
Chrome wants to start by making iron, but Senku says it's not that simple. He tells them about magnets and the earth's rotation, including the North Star. Kohaku says the star isn't true north, and Senku realizes the planet has moved slightly in the last three thousand years. Chrome uses a magnet and a leaf on top of a bowl of water to create a more accurate compass.

The next morning, Senku and the others go to the river to collect iron sand from the bed of the water. Senku claims they need more manpower, but Kohaku claims the villagers won't help strange sorcerers. A mysterious watermelon floats down the river, and it turns out to be Suika from the village. She wants to help prove she's useful, and Senku agrees to let her help despite her obscured vision.
Senku also learns that the villagers were taught about animals and stories from his time with Ruri, piquing his interest in the girl. They try to get to work on making iron, but burning wood doesn't provide a high enough temperature for iron-making. They try to use handmade fans to increase the temperature with wind inside a funnel, but they exhaust themselves well before they can even manage to melt the iron sand.
Ginro wants to check out what's going on, but Kinro won't allow him to leave his post. The blonde guard asks to switch spears with Kinro, but he refuses again. The next morning, Senku and Chrome notice they've nearly roped Ginro into an ally. Senku believes they need better bait for roping the villagers into helping them. Suika volunteers to gather information about what the villagers want and earns Senku's trust.

Suika hides in her watermelon and spies on all the villagers. She learns that many of the villagers want better food, and this gives Senku an idea about how to win them over. They collect foxtail millet and break it down into flour using the science of cooking. He adds eggs and potassium carbonate and molds them into noodles before combining them with other tasty ingredients. The smell invigorates Chrome and Kohaku, and Senku reveals that this incredibly tasty food is called ramen.
Chrome, Suika, and Kohaku all think ramen is amazing. Meanwhile, having tasted real ramen from his time, Senku thinks this ramen tastes horrible by comparison. They prepare a substantial portion of the fox millet ramen and bring a truck to the edge of the village, where the smell captures the attention of all the villagers. Senku believes he can colonize the village using the scientific food ramen.
Characters
- Chrome
- Ginro
- Senku Ishigami
- Kinro
- Kohaku
- Jasper
- Ruri
- Turquoise
- Azura (Debut)
- En (Debut)
- Garnet (Debut)
- Kokuyo (Debut)
- Mantle (Debut)
- Natri (Debut)
- Ruby (Debut)
- Sapphire (Debut)
- Shovel (Debut)
- Suika (Debut)
- Kaseki (Cameo)
Locations
- Ishigami Village
- Chrome's Shed
Inventions
- Iron Sand
- Foxtail Millet Ramen
Anime to Manga Differences
- There are many adjustments made in the anime during the introduction part of the episode:
- The cameo Kaseki appearance is placed on a boat with Ginro.
- Magma is seen holding an axe in front of a watermelon field instead of holding a bear.
- A shot of ugly Kohaku's angry face is omitted in the anime.
- A slight backstory of Suika is omitted in the anime.
- The second encounter of Senku with Kinro and Ginro is omitted from the anime.
- There are several additional scenes added during Kohaku harvesting the foxtail millet.
- There are no descriptions of the millet water separation method in the anime.
- The side story about the Chrome vs. Senku arithmetic fight is omitted in the anime.
Prologue Saga | ||
Chapters | 1 • 2 • 3 • 4 | |
Episodes | 1 • 2 | |
Chapters | 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 | |
Episodes | 3 • 4 • 5 | |
Ishigami Village Saga | ||
Chapters | 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 • 26 • 27 • 28 • 29 • 30 • 31 • 32 • 33 | |
Episodes | 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 | |
Chapters | 34 • 35 • 36 • 37 • 38 • 39 • 40 | |
Episodes | 13 • 14• 15 | |
Chapters | 41 • 42 • 43 • 44 • 45 | |
Episodes | 16 • 17 | |
Stone Wars Saga | ||
Chapters | 46 • 47 • 48 • 49 • 50 | |
Episodes | 18 • 19 | |
Chapters | 51 • 52 • 53 • 54 • 55 • 56 • 57 • 58 • 59 • 60 • 61 • 62 • 63 • 64 • 65 • 66 • 67 • 68 • 69 • 70 • 71 • 72 • 73 • 74 • 75 • 76 • 77 • 78 • 79 • 80 • 81 • 82 | |
Episodes | 20 • 21 • 22 • 23 • 24 • 25 • 26 • 27 • 28 • 29 • 30 • 31 • 32 • 33 • 34 • 35 | |
Source of the Petrification Saga | ||
Chapters | 83 • 84 • 85 • 86 • 87 • 88 • 89 • 90 • 91 • 92 • 93 • 94 • 95 • 96 • 97 • 98 • 99 • 100 | |
Episodes | 35 • Ryusui • 36 • 37 • 38 • 39 • 40 | |
Chapters | 101 • 102 • 103 • 104 • 105 • 106 • 107 • 108 • 109 • 110 • 111 • 112 • 113 • 114 • 115 • 116 • 117 • 118 • 119 • 120 • 121 • 122 • 123 • 124 • 125 • 126 • 127 • 128 • 129 • 130 • 131 • 132 • 133 • 134 • 135 • 136 • 137 • 138 | |
Episodes | 41 • 42 • 43 • 44 • 45 • 46 • 47 • 48 • 49 • 50 • 51 • 52 • 53 • 54 | |
The Truth of the Petrification Saga | ||
Chapters | 139 • 140 • 141 • 142 • 143 • 144 • 145 • 146 • 147 • 148 • 149 • 150 • 151 • 152 • 153 • 154 • 155 • 156 • 157 • 158 • 159 • 160 • 161 • 162 • 163 • 164 • 165 • 166 • 167 • 168 • 169 | |
Episodes | 55 • 56 • 57 • 58 • 59 • 60 • 61 • 62 • 63 • 64 • 65 • 66 • 67 • 68 • 69 | |
Chapters | 170 • 171 • 172 • 173 • 174 • 175 • 176 • 177 • 178 • 179 • 180 • 181 • 182 • 183 • 184 • 185 • 186 • 187 • 188 • 189 • 190 • 191 • 192 • 193 | |
Episodes | ||
Chapters | 194 • 195 • 196 • 197 • 198 • 199 • 200 | |
Episodes | ||
Chapters | 201 • 202 • 203 • 204 • 205 • 206 • 207 • 208 • 209 • 210 • 211 • 212 | |
Episodes | ||
Stone to Space Saga | ||
Chapters | 213 • 214 • 215 • 216 • 217 • 218 • 219 • 220 • 221 • 222 • 223 • 224 • 225 • 226 • 227 • 228 • 229 • 230 • 231 • 232 | |
Episodes |