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Dr. Stone Wiki

Kokuyo (コクヨウ Kokuyou) is the father of Kohaku and Ruri, and was the previous chief[5] of Ishigami Village before Senku.

Despite not being the chief anymore, he serves as something of a co-leader of Ishigami Village, focusing on more practical concerns like food gathering, while Senku focuses on scientific advancement.


Kokuyo is a large, muscular middle-aged man with blond hair tied into a ponytail. He has gruff, hardened facial features with thick eyebrows, a somewhat large nose, and intense brown eyes. His long brown beard and goatee notably do not match his blond hair, and for clothes, he wears a blue robe with a white under cloth with a rope tied around his neck.


Initially, he is a harsh man who threatens with disowning Kohaku as his daughter for constantly going against him, such as entering the village tournament and winning to prevent Magma from becoming the new chief and marrying Ruri or bringing an unknown figure to the village.[6] He also didn't seem to mind Magma being the new chief, despite knowing that he didn't care for Ruri's well being. However, he does care for Ruri, as he worries for her health. He seems to want to become closer to his daughters and becomes saddened when they don't reciprocate. For example, he gave Kohaku her shield and when Senku suggested using it in one of his inventions, he shyly remarks that he is fine with it as long as Kohaku is, but clearly expects her to reject. He is saddened when she shows no sentiment towards the shield and quickly uses it in the invention. He seems to later reconcile with Kohaku, as he realizes how hard she worked carrying water for her sister every day to delay her illness.

He is wary of outsiders, especially Senku[6][5], but later grows to accept him and states that making him the leader was not a mistake.

He can be rather simpleminded, believing the tungsten that Senku brought was for throwing at enemies and not realizing that he was going to use it for an experiment. Ruri and Kohaku claim this is because he came from the older generation. Despite his practical and initially simple view of the world, he develops an appreciation for the comforts that the Kingdom of Science has brought his village and its people. He praises Senku for not only being an effective leader and worthy successor, but someone who has brought out a crucial element for survival: fun.

Abilities and Skills

  • Physical Strength: Kokuyo is one of the primary fighters of Ishigami Village. It can be said he is the strongest of his time as he was the winner of his Grand Bout[7]. He is often seen leading an attack among the strongest villagers such as Kohaku and Magma.
  • Swordsmanship: Kokuyo is seen using a Katana to defend the village when they are attacked by Hyoga[8], and when he assisted in attacking the miracle cave.
  • Leadership: Being the chief of Ishigami village for many years, he has become a strong leader, often thinking of the villagers safety. He is upset when the village rules are broken, even disowning his own daughter, Kohaku, for breaking said rules. When Homura was coming towards the village, Kokuyo immedietly ordered seniors and children to take shelter, and told everyone else to surround her[9], and despite him no longer being chief, they do as he says anyways, showing the respect the village has for him as a leader.


He won one of the previous village games and became chief. In commemoration of his victory, Kaseki made a shield for him. Some years later, he would pass the shield on to Kohaku. Ruri was stricken with pneumonia at some point in the past, and he began to make plans for Kohaku to learn the Hundred Tales and succeed Ruri as priestess in the event of her death. Kohaku refused to go along with this plan, creating a rift between Kokuyo and Kohaku that would continue into the present.[10]


Kingdom of Science Arc

With Senku's arrival to the village, Kokyuo is appalled by Kohaku's disobedience. Angered, he says he might eventually disown her given how she constantly breaks village's rules.[6]

After Senku, Chrome, Kohaku and Suika make ramen and goad some villagers into trying it, Kokuyo is becoming more and more concerned for the village. Jasper asks Kokuyo whether or not they should go out to eat themselves, which Kokuyo rebukes. The former gets elbowed by his wife for making such a suggestion, as Ruri gets worried about what Kohaku's business with an unknown figure is.[11]

Village Games Arc

Kokuyo compliments the weather on the day of the tournament, and asks Turquoise whether the preparations are set. When Turquoise berates her husband for allowing Kohaku into the fight, Kokuyo states that it's fine - he wouldn't let a village chief be someone who can't beat a woman. Jasper then informs Kokuyo that Senku has also joined the village games.[12]

When Ruri approaches Senku to inquire him about his surname, she collapses from her ailment. Kokuyo rushes towards his daughter, scolding Jasper for letting her walk while feeling sick.[13]

He comments on Senku's cunning nature as the latter uses an unorthodox technique with his spear to hit Ginro in the groin.[14] Soon after, Senku wins by Chrome getting disqualified from fainting and becomes the village chief. An angry Kokuyo states that he won't accept an outsider like Senku as the village chief, only to be rebuked by Senku who calls him a former village chief and says he has no interest in what a former figure of authority has to say. Once Senku acquires alcohol for the antibiotic formula, he immediately divorces Ruri and drags Kohaku and Kaseki away with him, further shocking the former village chief who orders Senku to be caught but is stopped by Kinro who vouches for the mysterious scientist. Once the cure is finished, an uneasy Kokuyo observes Ruri taking a suspicious drug for her illness.[15]

Once Ruri's condition worsens, Kokuyo blames Senku who fed the drugs to her beforehand. Senku confirms this, however he states that the reason behind the more critical condition is because bacteria in question is mobilizing forces as its existence is threatened. Kokuyo goes on to call it sorcery, still angry and attempting to attack him. His attack is stopped by Kohaku who states she believes in Senku, while the rest of the group also nods in unison. After continuous consumption of the drug, Ruri is finally able to walk normally again, having been cured of the ailment. Kokuyo and his other daughter cry tears of happiness, seeing their relative finally well again. The former chief officially crowns Senku the new leader of the Ishigami Village.[16]

Vs. Hyoga Arc

He stops Kohaku from getting involved in the battle with Kinro and Hyoga, saying that she would have no chance fighting a spear wielder on a thin bridge.[17]

Kokuyo later defends the village from Hyoga and his men with the katanas that Senku, Chrome, and Kaseki make.[18] Kokuyo and the rest of the warriors are quickly dispatched by Hyoga, whose spear breaks upon exerting too much force - thanks to Gen tampering with it prior to the second invasion.[8]

Kokuyo attempts to fight Homura after she sets the village on fire, but she escapes. He leads the evac efforts for the village as it burns down. Kokuyo later congratulates Suika on leading the enemy away and celebrates with the village their win over the first battle in the war.[19]

Communications Arc

Once the cotton candy machine is crafted as a part of the cellphone making process, Kokuyo enjoys the taste of the sweet along with the rest of the villagers.[20]

Kokuyo accepting Senku as the new chief.

While discussing the problem of manpower in preparation of the cellphone, Kokuyo mentions that a portion of people needs to be delegated to ready the village for the winter. As Senku comes up with an idea of utilizing gears to ease the burden on the working force, Kokuyo is shocked to see that Kohaku readily gives up her shield which he gave her as a memento of the past to be used as a gear itself.[7]

Kokuyo is amazed by a method to preserve meat over winter by bottling the food in a glass pots.[21] The village leader announces the sunrise of a new year, and is bewildered by the properties of tungsten, a material needed for Kingdom of Science's progress.[22] Once acquiring various types of jewels, a satisfied Kokuyo states that they will be useful in defending the village, comically misunderstanding what they're designed for.[23]

He is later seen when Senku plays the record his father left him, being amazed to hear the village founder. Kokuyo sadly remarks to himself that Kohaku is even more of a distant child after she calls Senku's treatment of his father cold.[24]

Treasure Island Arc

He travels on the Perseus to gather a way of creating more revival formula.

During the voyage, he is upset at the possibility of the Why-man being on the new island. He complains to Soyuz after he revealed the truth about himself and his past. However, he relents after realizing how hard it was for him.[25]

He is shocked to discover Suika stowed away after Ryusui discovered her hiding.[26]

He is petrified by Kirisame but gets revived by Senku.

Kokuyo is petrified once again, because of Ibara's last resort.

New America City Arc

Kokuyo bears witness to the training of his daughter and Kirisame, remarking on their skill.[27]

Kokuyo returns to Ishigami Village while his allies journey to America.

South America Arc

He witnesses the Petrification beam heading over the Horizon and knowing the meaning he tells his fellows to assume a defensive position so they will not be damaged while stone. He is then petrified with the villagers.[28]

Chapter Appearances

Chapter Appearances
Kingdom of Science Arc
13. Part 1: Stone World: The Beginning Absent
14. Those Who Have Faith Absent
15. Two Kingdoms of the Stone World Absent
16. Kohaku Absent
17. Nasty Looks Pictured
18. Sorcery Showdown Absent
19. Two Million Years of Being Absent
20. Stone Road Debut
21. Dawn of Iron Absent
22. Survival Gourmet Absent
23. The Smooth Talker Appears
24. Lightning Speed!!! Absent
25. By These Hands, the Light of Science Absent
26. A Shadow Alliance Absent
27. A Certain Scientists Wish Appears
28. Clear World Absent
29. Senku's Lab Flashback
30. Death Green Absent
31. Friends Have Each Other's Backs Flashback
32. Brain & Heart Absent
33. Baaad Chemicals Appears
Village Games Arc
34. Sneaky Grand Bout Strategy Appears
35. The Masked Warrior Appears
36. Kinro and Ginro Appears
37. Science-User Chrome Absent
38. Master of Flame Absent
39. And the Winner is... Appears
40. Two Million Years in the Making Appears
Village Origins Arc
41. Doctor Stone Appears
42. Tale for the Ages Absent
43. Humanity's Final Six Absent
44. One Hundred Nights, One Thousand Skies Pictured
45. Epilogue of Part 1 (End of Part 1) Part 2: Stone Wars Pictured
Vs. Hyoga Arc
46. Stone Wars Pictured
47. Science Vs. Power Pictured
48. Blades of Science Pictured
49. To the Present Appears
50. Humanity's Greatest Weapon Absent
Communications Arc
51. Sweets for the Stone World Appears
52. Age of Energy Appears
53. Hard Knocks Crafting Club Appears
54. Flickering Blue Jewel Pictured
55. Treasure Dungeon Push Start Absent
56. The Treasure Pictured
57. Heat Heart Appears
58. Wave of Science Appears
59. Voices from Here to Infinity Absent
60. Angel's Song, Devil's Whisper Appears
61. Stone Wars Begin Appears
62. Double Chase Appears
63. Information Warfare Absent
64. Hotline Absent
65. Call From the Dead Appears
66. Liars and Truth Tellers Absent
67. Full Mobilization Appears
68. Flame of Revolution Absent
69. Steam Gorilla Appears
70. Paper Shield Appears
71. Prison Break Absent
72. Experience Points Absent
73. Top-Secret Mission Pictured
74. Fateful 20 Seconds Pictured
75. 20-Second Countdown Pictured
76. Final Battle Pictured
77. The Power of Science Appears
78. That Which Destroys or Saves Absent
79. For This Very Moment Absent
80. Humanity's Strongest Tag Team Pictured
81. Fingertip Absent
82. Epilogue of Stone Wars (End of Part 2) Absent
Age of Exploration Arc
83. Dr. Stone Appears
84. People = Power Appears
85. Ultimate Resource Absent
86. Money Absent
87. Senku's Department Store Absent
88. Wings of Humanity Absent
89. Adventures Absent
90. New World Map Absent
91. Need Bread? Start with Wheat Absent
92. Desire is Noble Absent
93. The First Shot Is Yours Absent
94. The Scent of Black Gold Absent
95. First Contact Absent
96. Eye of Science Absent
97. The Joy of Leadership Absent
98. Ryusui Appears
99. Kingdom of Science Photo Journal Absent
100. Origin of the 100 Tales Pictured
Treasure Island Arc
101. Treasure Chest Appears
102. Perseus, Ship of Science Absent
103. Light of Hope and Despair Appears
104. Men of Forensics Absent
105. The Island's Great Beauty Absent
106. The Secret of Petrification Absent
107. To the Trump Card Science Vessel Absent
108. Two Trump Cards Absent
109. The Great Escape Absent
110. Beautiful Science Absent
111. Science Wars Absent
112. King of Three Dimensions Absent
113. Cryptography Science Absent
114. Silently, Science Pierces the Stone Absent
115. One Second, One Grain Absent
116. Miracle in Hand Absent
117. The Kingdom of Science Strikes Back Absent
118. Silent Soldiers Absent
119. Science Soldiers Absent
120. Top Secret Absent
121. Medusa's True Face Absent
122. Brain-Battle Puzzle Pieces Absent
123. The Battle of Wits' Deal Game Absent
124. The Invention of God and the Devil Absent
125. The Decisive Three-Dimensional Battle Absent
126. A 3-D Strategy Absent
127. Medusa and Perseus Absent
128. Island-Wide Battle Royale Absent
129. Joker Absent
130. Devil's Choice Absent
131. Nasty Crimes Absent
132. The Strongest Weapon Is... Absent
133. Flash of Destruction Absent
134. Commander Faceoff Absent
135. Counting Absent
136. Medusa Vs. Science Absent
137. Last Man Standing Absent
138. End Of Part 3 Absent
New America City Arc
139. First Dream Appears
140. New World Plots Absent
141. First Team Absent
142. World Power Absent
143. Ryusui vs. Senku Absent
144. Ryusui & Gen vs. Senku & Kohaku Absent
145. Bar Francois Absent
146. Bar Francois: Bitters Absent
147. Science Journey Absent
148. Pioneers of Earth Absent
149. Light Lure in Darkness Absent
150. Righteous Science User Absent
151. Dr. X Absent
152. Doctor Vs. Doctor Absent
153. Science Wars Absent
154. Spy vs. Spy Absent
155. Science Is Elegant Pictured
156. Two Scientists Absent
157. Same Time, Same Place Absent
158. Who's the Scientist? Absent
159. Lock On Absent
160. Gunshots Echo Absent
161. Craft Wars Absent
162. Down the Earth-Stained Path Absent
163. Multifront Final Battle Absent
164. Re-Lock On Absent
165. Know the Rules, Make the Rules Absent
166. Ultimate Knight Absent
167. Different Strokes Absent
168. Corn City: Population One Million Absent
169. RISK or HEART Absent
South America Arc
170. Staring Up at the Same Moon Absent
171. Staring at the Same Light Absent
172. Marked with an "X" of Wisdom Absent
173. Earth Race Absent
174. The Specter of the Panama Canal Absent
175. Ultra Race Across South America Absent
176. Net-Breaking Battle Plan Absent
177. Medusa Mechanism Absent
178. Science Scales Mountains Absent
179. Bonds on the High-Wire Absent
180. Sickening Yet Beautiful Absent
181. New World Science Absent
182. Diamond Heart Absent
183. Stone Sanctuary Absent
184. Fort Medusa Absent
185. Lovely Cleavage Plane Absent
186. To Each Their Own Blade Absent
187. Cyber Guerilla Absent
188. What I Once Sought to Destroy Absent
189. Our Dr. Stone Absent
190. Science Transcends Life Absent
191. Divine Scream, Down to Earth Absent
192. Until We Meet Again Absent
193. Our Stone World Appears
New Stone World Arc
194. Homo Sapiens, All Alone Petrified
195. Treasure Hunter, All Alone Absent
196. Scientist, All Alone Absent
197. A Stony Eden and Its Forbidden Fruit Absent
198. Whole New World Absent
199. Superalloys Absent
200. Future Engine Absent


  • His name is derived from the Japanese word for obsidian, 黒曜石 (こくようせき) made up from the characters Black ( Kuro) and Jewel (曜石 Youseki).


  1. Dr. Stone Manga: Volume 22 — Extras
  2. Dr. Stone Manga: Volume 19 — Extras
  3. Dr. Stone Manga: Chapter 193
  4. Dr. Stone Manga — Chapter 193, Kokuyo is petrified along with the rest of the world.
  5. 5.0 5.1 Dr. Stone Manga: Chapter 23
  6. 6.0 6.1 6.2 Dr. Stone Manga: Chapter 20
  7. 7.0 7.1 Dr. Stone Manga: Chapter 52
  8. 8.0 8.1 Dr. Stone Manga: Chapter 48
  9. Dr. Stone Manga: Chapter 62
  10. Dr. Stone Manga: Chapter 31
  11. Dr. Stone Manga: Chapter 21
  12. Dr. Stone Manga: Chapter 33
  13. Dr. Stone Manga: Chapter 34
  14. Dr. Stone Manga: Chapter 39
  15. Dr. Stone Manga: Chapter 40
  16. Dr. Stone Manga: Chapter 41
  17. Dr. Stone Manga: Chapter 46
  18. Dr. Stone Manga: Chapter 47
  19. Dr. Stone Manga: Chapter 49
  20. Dr. Stone Manga: Chapter 51
  21. Dr. Stone Manga: Chapter 53
  22. Dr. Stone Manga: Chapter 54
  23. Dr. Stone Manga: Chapter 57
  24. Dr. Stone Manga: Chapter 60
  25. Dr. Stone Manga: Chapter 102
  26. Dr. Stone Manga: Chapter 103
  27. Dr. Stone Manga: Chapter 139
  28. Dr. Stone Manga: Chapter 192

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