Dr. Stone Wiki
Dr. Stone Wiki


Prior to the Petrification, Dr. Xeno was childhood friends with Stanley. In his adult life, he became a NASA scientist.[1]


Xeno's hypothetical plans of dictatorship.

One day at NASA, they received a strange email from a young boy called Senku Ishigami. While his colleagues were hesitant to respond, Xeno replied and tells Senku what he would need to conduct his experiment. Xeno continued to correspond with Senku about science. Sometime later, he was asked on what he would do if the world was sent back to the Stone Age and he responded that he would serve as a dictator over the less sophisticated. In response, Byakuya Ishigami laughed at this in good fun. Five years later, Byakuya announced his son Senku would visit and Xeno is shocked to learn the boy he taught was the son of his colleague and will be at NASA. Xeno found Senku while he admired a monument of a ship and approached by silently standing next to him, both obviously knowing each other. When an excited Byakuya greets his son and ask why he seems spaced out, Xeno is seen walking away.[2]


Xeno petrified with Stanley

Xeno began investigating the petrified birds and wondered about the cause. He met with the military unit led by Stanley Snyder at the NASA headquarters. Xeno explained his findings before a mysterious light appeared. Xeno along with the rest of the world was petrified for thousands of years. He maintained consciousness in that time.

On April 1, 5739, Xeno was freed and after using the platinum from Carlos' ring, constructed the fortress in San Francisco. Xeno then put his group, consisting of people from his meeting just before the Petrification under his employ. [3] [4]


New America City Arc[]

Stanley contacted Xeno about how the enemy took down his aircraft, while Xeno informed the former about how the formula was concocted. Stanley ends his lecture and concludes the group has a skilled science user like Xeno. [5]

Xeno interrogates Gen

Xeno interrogates Gen

Dr. Xeno is present in the fortress factory when Stanley brings Gen Asagiri in for questioning. Stanley says that it's no wonder Dr. Xeno is found in his factory as Gen is put onto something that looked like a polygraph test. Dr. Xeno introduced himself along with Stanley, before intently questioning Gen on who he is and where he came from. After the latter gives his name and some of his history, Xeno is fascinated to hear that the man comes from Japan, having taken to face the dangers of the stone world to reach America. After Gen describes his leader's behavior, Xeno makes a point that the stranger may either be honest to a fault or a very good liar. He doesn't mind however, saying that he is fond of both types. At the end, Xeno inquires on the leader scientist's name, to which Gen replies with "Dr. Taiju".[6]

Xeno comes into contact with KoS

Xeno contacts the enemy

He eventually locates the frequency of the group's communication and contacts them in order to start negotiating with Taiju, who is advised by Senku on what to say. Xeno states that they have a clear technological advantage, having a factory that can produce mass amounts of ammunition. He makes them an offer to completely surrender and serve him since his manpower is lacking as he has no means to depetrify the statues. Xeno also mentions that only those who have been aware during all 3,700 years can be revived with nitric acid alone, thereby unintentionally telling the group he has no idea about the revival fluid. As Taiju innocently attempts to answer Xeno's question about how to make the miracle formula, he is stopped by Ryusui who informs him they will simply crush the group once they have the manpower to do so. Xeno's offer is rejected, and he promptly ends the call.[3]

When Stanley decides to eliminate the science user of the Kingdom of Science, Xeno tells a protesting Gen if Stanley says that he can do it then it will get done.[7]

Xeno is later seen excited by the idea of ending this conflict by finding and eliminating the science user.[8]

A short time later, he presumably got word of Stanley's plan and compliments the solution to simply snipe the leader.[9]

Xeno later overheard Max's transmission and heard the word Senku. Recognizing the name as that of his former apprentice, he ordered Stanley not to shoot Taiju who he realized was a proxy to throw them off. [10]


"The enemy scientist is... Senku."

Xeno then described Senku as his former apprentice. Repeating his words, that Taiju is not the enemy scientist, but Senku is. Stanley asks Xeno to identify Senku. Having a recording of the Perseus' transmissions, while reminiscing about his past with Senku. Stanley complains that he can't hear their voices, but Xeno says that he'll use Senku's voice to calculate his height. Xeno estimates his height to be about 5'8'' and his age to be 19. After Stanley spots his target, he questions Xeno if he really wants his former ward dead. Thinking it over, Xeno realizes Senku will oppose his plans. He then gives Stanley consent to take the shot.[11]

Very soon, the Petrification Weapon is delivered to Xeno. Xeno listened to Gen describing it and though his followers are skeptical of Gen's words, Xeno plans to research the device. He and Dr. Brody continued their new project while having one of the soldiers prevent Gen from hearing.[12]

Sometime later, he and Brody completed their project, a submarine used to attack the Perseus.[13]

Very soon, Stanley reports the enemy has been defeated. At the castle, Xeno receives the report and relishes in his apparent victory. However, he gets a transmission from Senku to tell him that he was not the only one who sent his knight. Shocked, Xeno is then confronted by Tsukasa who holds him at swordpoint.[14]

Soon the rest of the group arrive, Xeno is fascinated they reached the area by tunneling. He takes note of Chrome's amazement with his technology before he is captured. A captive Xeno is taken by his enemies to a tunnel they made, he watches Chrome reveals that he anticipated the guards following and brought a bomb to close the tunnel. Chrome reluctantly stays behind to do so but a cave-in occurs. While stuck with Chrome, Xeno talks with him about how he is a descendant of the human survivors. The scientist says that he could be a commander if he joins with him since their allies are likely defeated and if they join together they can rule the stone world. Chrome refuses a tempting offer well stating because of Senku, he has learned not to use Science to control people. Xeno is shocked when Chrome contacts Senku to tell him that he was captured . [15]

Afterwards, Xeno is shocked to witness Senku and Ryusui arrive. He is shocked and amazed that his former pupil survived. He shares some words with his former apprentice, before Xeno tells him that he is already lost the battle because of Stanley commandeering the Perseus. He soon watches as more people come to join Senku. Xeno is taken by his enemies in one of his spare boats. Afterwards, he watches Senku and his group discuss how there's someone in the American colony who most likely would not want to see blood shed in contact Dr. Brody. Xeno watches Brody being uninterested in a truce until Senku makes him an offer. Xeno is greatly shocked when Senku reveals the ingredients to the revival formula. [16]

South America Arc[]

During the voyage, Xeno sat tied up before he overhears Senku's group discuss the origin of the Petrification beam. He soon asks them if they ever pondered that the Petrification is connected to signal coming from the moon, which surprises everyone. Seeing they already knew of it, however, Senku gets excited as Xeno hopes that they can work together to figure out the course of the personification and they proceed to exchange information.[17]

Senku and Xeno begin to listen to Byakuya's message, as he sadly laments over Byakuya and his long-dead companions. After briefly discussing how Byakuya set the mission, they decide to fulfill his desire of understanding the Petrification. Soon they start blowing bubbles, as a method to uncover the time difference for Petrification. When Chrome arrives with snacks, he is surprised not only to see Xeno free, but their supposed slacking until he is told why and they fill him on the situation. Xeno is impressed by Chrome deducing a method for the time difference.[18]

When they make a stop, they gather wood for fuel until Taiju (whose unlimited stamina allow him to go on) discovers lights in the sky spelling H-E-L-L and updates them on the situation. The morning after, Xeno and the others find a hanging pumpkin hut, as Tsukasa asked him if he knew who it belongs to but the latter does not until the inhabitant is revealed to be an unknown woman. After seeing her scary squinting expression, they realized that she needed glasses. Xeno and the woman soon recognize each other and he identified her as Chelsea Childe, while describing her to everyone. Xeno questioned Chelsea why she didn't reach his colony if she revived the previous year until realizing her poor eyesight and what choice she made to go in direction. He was later amazed by her wanting to gather rubber and build motorcycles.[19]

When Chelsea joins the team, Xeno watches as she is updated by Gen on the recent events like Whyman, their recent fleeing from Stanley, and the reason for the journey. After getting the gist of the situation, she excitedly calls Xeno a "bad guy" and decides to join Senku's group after refusing his offer to join him. After Ukyo announces the Stanley is catching up, and they don't have much time. However, the group get an idea to use Chelsea's kites as sails to move faster.[20]

The junior science group completed the motorcycles while taking a bound Xeno away, narrowly missing Stanley and his men who just arrived,[21]

As his unit start firing at the escaping motorcycles, Stanley goes to higher ground when they stop firing when the dust cloud means they risk hitting Xeno. Taking advantage of the fray, Xeno requests to be used as a shield to counter the enemy, something Hyoga obliges. After the soldiers stop firing, Xeno sends a message to Stanley by blinking in Morse code at him.[22]

While trekking through the Amazon rainforest, Xeno creates bug repellent from plants, stating that he rather not got bit if he is forced to tag along.[23]

After his warriors open fire on the fort, Xeno made his escape and reunited with Stanley, commenting his rescue took a while. He then had his men open fire on the revival team for the Revival Fluid, stating it was obvious they had some. With the beam approaching, they realize they had to be prepared for the worse. His attempts at seizing the revival fluid bottles from the Kingdom of Science's reach prove to no avail, as Suika made off with them. After the reach the fort, Xeno realized Senku's goal of creating a rig for someone on his side to revive. He was amazed by this feat.[24]

As the beam approaches, Xeno ponders on why Senku could not be more like him. He noted they were similar Xeno, both being scientists with a strong and devoted childhood friend. He asked the wounded Senku why he didn't join him because they could have had the world, as Senku reminds Xeno that while they were alike, the difference between them was their approach of Science. Accepting the answer, Xeno accepts defeat and was petrified, with Stanley surrendering not long after.[25]

New Stone World Arc[]

Seven years later, upon reviving and realizing that the fight against Why-man has taken on additional urgency, Senku gave Dr. Xeno a secret seventeenth helping of revival fluid. Senku, Chrome, and Tsukasa brief him on the discovery that petrification can allow someone to defy death. Xeno notes that they have a reason for telling him this news, as Senku shows him that Why-man's regular transmissions of "12,800,000 meters, 1 second" (the phrase that causes petrification rings to immediately petrify the earth) have stopped since the petrification seven years ago. Senku candidly tells Xeno that against such an unknown power, his own attempts at conquering the stone world were meaningless. Xeno agrees to help Senku build the rocket needed to confront the Whyman, remarking that after ten (living) years, the two of them are finally able to work together. The next day, the other three of the Five Generals - Gen, Ukyo, and Ryusui - sweeten the pot by showing him the statue of Stanley Snyder. When society is rebuilt, they point out, whether Stanley is seen by the courts as a solider or a murderer for his role in fighting the Kingdom of Science will depend on their testimony; the entire Kingdom agrees to testify to the former in exchange for Xeno's wholehearted cooperation. Xeno agrees, calling this an elegant trade, though Gen (who may have heard the prior conversation) suspects that his pride as a scientist is what truly motivates him to help. Xeno and Senku then begin their construction of a rocket.[26]

Xeno telling American Soldiers about Why Man

Xeno's specialty in the rocket building process involves the fusion of various superalloys in Brazil to make powerful engines, stronger cans, and radioactive compounds. He acknowledges that his practice of science involves many things the modern world would condemn him for. In what he calls an elegant arrangement where everyone performs the role best meant for them, he accepts unto himself the burden of being the scientist of darkness, doing the more unethical projects, freeing Senku to lead the others towards the future as a scientist of light. Much later, Xeno's followers are revived to aid in the construction of Superalloy City and from a radio, he informs them about Why-man and the alliance with the Kingdom of Science. After some days, the city is established with several people revived to inhabit it.[27]

Xeno continues his works on building the special heaters for melting the superalloys. Half a year later, Xeno makes his superalloy, inconel, and Senku finishes his liquid fuel. They test a rocket engine near the water and it works as intended, however it is only level 1. Xeno says they'll need a level 99 engine if they want to reach the moon. After it was decided the group will split into three teams, Xeno is assigned to lead the team staying in Superalloy City, consisting of himself, Maya, Tsukasa, Ginro and Matsukaze.[28]

Globetrotting Arc[]

The team in India needed to send some circuit diagrams to Corn City to help construct the computer. Xeno proposed an elegent solution: using a fax machine. Xeno tells Senku what design he's using and leaves the rest to him.[29]

Moon Mission Arc[]

Senku and Xeno's determination

Xeno and Senku's determination

After three years of work, Xeno arrives to Japan bringing with him a finished level 99 rocket engine, and both he and Senku are prideful over their work. He is later left at a loss for words when the rocket flips over on launch and lands in the water. He and Senku then deduce the faults of the previous rocket and create a second one, however on the second launch, it exploded completely, once again leaving Xeno at a loss for words. He comments on how even modern day rockets had these sorts of incidents. But his determination was unfaltering, and he and Senku would work for years on rocket after rocket, failure after failure, in order to perfect the craft.[30]

Chapter 216

Succesful rocket.

Finally, a rocket succeeded, and the first satellite was launched, much to the joy of Xeno and others. Xeno is later amazed by Kohaku's exceptional eyesight, and uses his specialties as a NASA scientist to confirm what she saw in the photograph was indeed Why-man.[31] He and Senku stand proud together, being cheered on for having finally discovered the assumed perpetrator of everything. During the "mega science conference" which demanded the mission used a two-way rocket instead of the planned one-way, Senku and Xeno represented the "super scientist" team. Xeno states that a two-way rocket requires 5 times the risk and time, and estimates it would take decades of work to complete. When Chrome presents his plan of having the rocket be launched in 5 pieces and then combined in space, both Xeno and Senku immediately recognize this plan as viable as the ISS was constructed similarly. Xeno comments on how NASA theorized about launching a piecemeal spaceship, but what stops these plans from going through is the design. A two-way rocket needs millions of individiual components to make the sections joinable. He does not believe the plan is realistic, even with all the professionals they have working on it.[32]

Xeno and Senku organize the world's first online meeting, and Xeno is the one to tell the people what the plan is, taking lead over Senku as a former world-famous scientist. He unites engineers around the world to share designs for the rocket using e-paper.[32] Xeno briefs the Kingdom of Science on the space mission, naming the hurdles they will need to overcome, and the unknowns. Xeno lists three people required for the job: a pilot, a scientist and a warrior.[33]

Stanley reuniting with Xeno

Stanley reminds himself of what his best friend Xeno's face feels like.

Xeno emphasizes the mystery of the space mission. They have no idea what their target, Why-man, is like, so moon combat is an unknown factor. He also warns that they do not know the petrification device's full abilties, so it could be capabale of launching multiple waves, rendering the revival fluid watches made by Joel useless.[34]

Xeno is told of Ryusui's decision to step down as the pilot, as there's someone who is both a much better pilot and sharpshooter: Stanley Snyder. Xeno remarks on the wise choice, but begins to question the others on what they would do if he and Stanley try to take over the world once more. Both Ryusui and Senku place their trust in him regardless, calling him "one of our leaders". Xeno becomes a hostage once again to assuage fears over reviving Stanley. Xeno awakens him, and hands him a cigarette and lighter. Immediately upon lighting the cigarette, Stanley asks "what's the job?". Xeno remarks that professionals are always quick. He then quizzes Stanley on some moon math, which Stan answers correctly, proving his abilities to far surpass that of Ryusui. Xeno asks Stanley if he's up for the task, which Stanley answers by puting his hand on Xeno's chin and carressing his lip for seemingly no reason, and responds "Sure. I am."[35]

Xeno and Senku are later installing the new touchscreens into the rocket, dressed in bunny suits. Once these are assembled, the moon rocket is finally complete.[36] The astronauts make their way to the rocket, and say their goodbyes to their loved ones. Xeno speaks to Stanley, dressed in a hazmat suit as to avoid contamination. He remarks on how both he and Stanley never planned for this showdown with Why-man, and how his science and Stan's battle prowess is once again about to take part in a war, to which Stan comments on how it isn't just them anymore. Xeno agrees, and says they are joined by the entire world. As a parting gift to his beloved, Xeno provides Stan with chewable tobacco, as he cannot smoke in space. Xeno is the one to take command in the launch center as the astronauts petrify themselves. Xeno begins the launch countdown from 10, and finally, the rocket is lifts off towards the moon.[37]


  1. Dr. Stone Manga: Chapter 155, Page 17
  2. Dr. Stone Manga: Chapter 156
  3. 3.0 3.1 Dr. Stone Manga: Chapter 152
  4. Dr. Stone Manga: Chapter 157
  5. Dr. Stone Manga: Chapter 150, Pages 15 - 17
  6. Dr. Stone Manga: Chapter 151
  7. Dr. Stone Manga: Chapter 153, Pages 14 - 16
  8. Dr. Stone Manga: Chapter 154, Page 1
  9. Dr. Stone Manga: Chapter 155, Page 1
  10. Dr. Stone Manga: Chapter 158, Pages 13 - 20
  11. Dr. Stone Manga: Chapter 159
  12. Dr. Stone Manga: Chapter 161
  13. Dr. Stone Manga: Chapter 165, Page 6
  14. Dr. Stone Manga: Chapter 166, Pages 17 - 20
  15. Dr. Stone Manga: Chapter 167
  16. Dr. Stone Manga: Chapter 168
  17. Dr. Stone Manga: Chapter 170, Pages 13 - 19
  18. Dr. Stone Manga: Chapter 171
  19. Dr. Stone Manga: Chapter 172
  20. Dr. Stone Manga: Chapter 173
  21. Dr. Stone Manga: Chapter 175
  22. Dr. Stone Manga: Chapter 176
  23. Dr. Stone Manga: Chapter 180, Page 6
  24. Dr. Stone Manga: Chapter 192
  25. Dr. Stone Manga: Chapter 193
  26. Dr. Stone Manga: Chapter 198
  27. Dr. Stone Manga: Chapter 199
  28. Dr. Stone Manga: Chapter 200
  29. Dr. Stone Manga: Chapter 207, Pages 3 - 4
  30. Dr. Stone Manga: Chapter 215
  31. Dr. Stone Manga: Chapter 216
  32. 32.0 32.1 Dr. Stone Manga: Chapter 218
  33. Dr. Stone Manga: Chapter 219, Pages 2 - 3
  34. Dr. Stone Manga: Chapter 220, Pages 7 - 10
  35. Dr. Stone Manga: Chapter 221
  36. Dr. Stone Manga: Chapter 222, Pages 15 - 19
  37. Dr. Stone Manga: Chapter 223