Senku Ishigami/Relationships

## Family

### Byakuya Ishigami

Senku was Byakuya's adoptive son and the two got along well despite their different personalities. They shared a very similar outlook in life and Senku held a lot of respect for Byakuya and the upbringing he gave him.

Byakuya encouraged him to pursue science and even sold his car in order to give Senku the opportunity to explore his scientific interest. In return, Senku helped Byakuya become an astronaut. Before going into space, Byakuya promised to bring back souvenirs for him, something that Senku was amused to see streamed on a live broadcast.

In the thousands of years after the petrification event, Senku discovered that his father was one of the founders of the Ishigami Village and had created the 100 Tales in hopes that perhaps they would be of use to Senku if he miraculously ever escaped the stone.

Although Senku in not outwardly affectionate, he cared for his father and was sad to find out that he survived the Petrification, and passed away three thousand years prior. Senku even shed tears at his father's grave, but was overall pleased his father held such faith in him to restore the world.

He appears to think of him from time to time and he was happy to hear his voice from the recording left behind. During the time on Treasure Island, Senku also reflected on Byakuya being there with his comrades.

Years later when Senku eventually makes it to space, Xeno allows him some time to himself to mourn before the rest of the astronauts are revived and Senku later shares ramen with them, same as Byakuya did back in his day. A few more years after the ordeal on the moon, Senku is revealed to be working on a time-machine and when its ability to save all remains victims of the petrification is discussed, he muses of his father and the rest of the astronaut team.

## Friends

### Taiju Oki

Taiju and Senku have been friends since childhood and Taiju often protected Senku from bullies. This led Senku to develop a deep sense of respect and trust towards Taiju, even though he is an airhead.

When Senku was depetrified, he did everything he could to survive, but admitted that he needed Taiju and his endurance to overcome the obstacles to come. Taiju was the first person that Senku revived and he later becomes a major part of Senku's plans to expand the Kingdom of Science, his strength and endurance proving vital to the Power Team.

While the two are pretty much polar opposites in pretty much every way, they are very similar in that they are both very resilient in the face of adversity. Taiju has an unconditional trust in Senku, despite not being able to understand the majority of his friend's plans, but manages to contribute with bouts of insight and his enormous strength of will.

### Yuzuriha Ogawa

Yuzuriha and Senku are friends through Taiju. Senku knows how deeply Taiju loves Yuzuriha (and vice versa) and, prior to the petrification, was confident that Yuzuriha would accept Taiju's confession.

Once she revived, he wanted her and Taiju to escape from Tsukasa. He is even willing to sacrifice himself to protect her and gives the depetrification formula to Tsukasa  In return, Yuzuriha tends to him and is the one who revives him from Tsukasa's attack. She also agrees to his request to act as a spy on Tsukasa.

Following the end of the Stone Wars, she becomes an official member of the Kingdom and her incredible ability for crafts and tailoring becomes indispensable to the Kingdom of Science. Senku often unloads heavy work on her as he knows she can handle it.

Yuzuriha is also one of the few people not put off by Senku's lecture or experimental tests, since she has experience with it. Furthermore, she was aware that he had an ulterior motive, when he was oddly nice to Luna.

### Kohaku

Kohaku is the first person born after petrification that Senku meets. Despite their initial troubled encounter (in which Senku rescued her, followed by both of them making bad impressions on each other) they get along very well and would develop a deep seated trust on each other, their capabilities, and willingness to hold their promises.

Kohaku's allegiance to Senku was born at a place of both admiration for his perseverance and methodical ways, and her refusing to back down and accept her initial defeat against Tsukasa; thus accepting to help Senku fight him, and create his kingdom of science to that end.

As she became his only available ally, Senku became immediately reliant on her. She would be his initial foothold into Ishigami Village, but at the same time she would use force to protect him from the villagers. Additionally, her strength and agility meant that she could carry out a lot of physical labor efficently (Senku even allowing himself to laze around while she worked alone, much to her anger), which was especially crucial in the early days of the kingdom of science.

Senku often pokes fun at her behavior and strength by calling her “lioness” which she finds to be extremely rude, but she does not retaliate as violently towards him as when other people call her names. Furthermore, they are both critical of the shortcomings of each other's personalities, such as Kohaku's temper and Senku's tendency to act evil and exploitative.

On rare occasions Kohaku has shown some deeper yet ambiguous emotional attachment to Senku. Other than teasing him or miswording her own thoughts, she doesn't make any romantic advances, and in the former case Senku does not even take them into consideration. While Senku is quick to deflect any attempts from anyone to show him affection physically (and he was visibly put off when Gen set up a scenario in which Kohaku had to kiss him to fool an enemy, something that she also seemed to be displeased with), he was understanding enough to allow her to hug him when they reunited after their triumph at Treasure island where she was petrified for the first time, though he did not hug her back. Kirisame became very flustered upon witnessing this display, having been previously misled to believe they were a couple, however Amaryllis corrected her on the nature of their hug.

After treasure island, they would not share such emotional moments for the remainder of the series, as the spotlight shifted to Senku's interactions with other characters, though their reunion in the one-shot chapter, Dr. Stone: Terraforming, closely mimicked their aforementioned reencounter in Treasure Island several years down the line. Kohaku embraced him, and although he gave in, he didn't hold her in correspondingly. She further suggested that Senku sees her as a partner with whom to face difficulties together. Senku however only responded in agreement to the notion that she would have been more likely to survive if he had left her petrified yet he didn't.

During the events of Dr. STONE: 4D Science, Chelsea appears to ask Senku who he’s interested in marrying, and if it’s Kohaku or Luna. He responds that he doesn’t just get to pick one as they’re not objects. This response shocked many who had come to see him as having no interest nor tact in regards to emotional matters, which he protested against. Kohaku comments that she’s open to the idea of marrying Senku if given the chance. Senku simply responds that he doesn’t have time for it.

In the second chapter of Dr. Stone 4D Science, there is a brief panel of Senku and Kohaku standing very close.

### Chrome

Chrome initially attempts to set up a rivarly with Senku as he takes pride on being the greatest (though also the only) sorcerer in Ishigami Village. Seeing him show up and defy his self perceived superiority, he hoped a display of his skills would either scare him away or make him want to become an apprentice, yet the 'sorcery showdown' that he would set up leaves Senku as the victor. despite having no interest in rivaling him.

Senku is initially unimpressed by Chrome's attempts to wow him, along with Kohaku, Kinro and Ginro, but he quickly abandons this perception as he realizes that all the demonstrations, which to Senku are very basic, were discovered by Chrome all on his own with materials he had collected himself.

The two strike up an alliance rather quickly after Chrome loses to him, and Senku is very impressed when Chrome later shows him to his rock stash. After he checks out all the material and Chrome talks about his initial goal behind gathering them, Senku decides to tell him about humanity's past achievements which moves Chrome to tears and inspires him to officially join forces with Senku to combat Ruri's illness.

Chrome quickly becomes one of Senku's main allies and a deeply loyal friend. He does not hesitate to step up to Senku when necessary and is willing to put his life on the line in order to look after him as is demonstrated when they set on their mission to collect sulfuric acid. Similarly, when Senku intended to carry out a suicide mission to defeat Whyman on the moon, Chrome, along with Suika, spent years of work learning all the science and mathematics involved in spaceflight in order to keep him alive with them.

Through the course of their adventure it is evident that Senku holds Chrome in high regard and does not hesitate to allow Chrome to his own devices in multiple occasions, fully trusting that Chrome's creativity will not fail to deliver, even if he considers the results Chrome brings to the table to be crude at times.

Senku sees himself in Chrome and cherishes his passion for science.

### Gen Asagiri

Senku and Gen are very good friends.

He had heard of Gen prior to the Petrification, since Gen had published a book that was popular with Senku's classmates. Senku, upon their first real-life meeting, calles said psychology book 'trashy' - which Gen pretended to be mildly offended by - and it may have affected his opinion of Gen negatively prior to them being acquainted.

They first meet when Senku cooks ramen for the Ishigami Village, he realizes Gen is a modern timer after Gen slips in to eat ramen and mentions cola in order to attract his attention. Originally sent by Tsukasa as a spy, Gen later defects to work with Senku. Realizing that he can revive science, he becomes one of Senku's most trusted retainers to manipulate others and advance Senku's plans. Senku himself has no problems with Gen being a turncoat and becomes close friends with him. As a gesture of good faith, Senku recreates Gen's favorite drink, cola.

The two are both intellectual equals, though Gen is more talented in the science of psychology and the art of manipulation and lacks in most fields of physical scientific knowledge. He assists Senku by manipulating people into following Senku's orders, facilitating cooperation, and helping Senku prepare for the bloodless war against Tsukasa. While Gen initially claims that he joined Senku's army for the benefits, he later admits that he had seen Senku write his liberation date and name on a stone, as he became fascinated with the person who could not only know the year and time they were de-petrified, but also swore to bring back science, telling Senku he already liked him a lot before they met. Gen even goes so far as to have the Ishigami village help him build a telescope for Senku's birthday, something that was greatly appreciated.

Senku himself greatly trusts Gen with his plans and the two enjoy scheming together, such as tricking Ryusui into buying lots of items, such as clothes and sportswear, so that they would have funds to buy oil from him. Gen is frequently amazed by Senku's inventions, often acting as the straight man to the many amazing scientific developments Senku accomplishes and holds great faith in him. In turn, Senku acknowledges Gen as not being completely devoid of a moral compass, despite Gen claiming to be the most shallow man he'll ever meet.

### Suika

Suika first meets Senku while he, Chrome and Kohaku are gathering black sand in the nearby river. She wants to help them, as she was often ridiculed and was never of help to others. She immediately becomes attached to Senku after he does not ridicule her for wearing a melon on her head or ask her about it (though Kohaku and Chrome point out that he more than likely didn't care).

He is genuinely impressed by her stealth and ability to hide and gather information, employing her to find out what the villagers like so he could use science to bait them to his side. Later, as thanks, he makes glasses for her when he learns she wears the melon rind to see better (as she is nearsighted and the pinhole effect of wearing the melon helps her to see). He ensures the first thing she sees are sunflowers and she becomes one of his most loyal friends, often helping him gather information and assisting in his labor-intensive work.

He shows a good deal of trust in her abilities along with care for her. When she befriends a boar, she worries Francois will cook it and Senku implicitly asks Francois to allow her to keep the pig as a pet. He similarly trusts her to help bring the lab to him when she was the only one not petrified by the Treasure Island tribe who boarded and took the items of the Perseus.

During the impending second petrification event, Senku places his faith in Suika to revive everyone. His faith was well place because she was able to complete the revival formula after seven years with him being the first person she revived.

### Kaseki

Senku constantly works with Kaseki in restoring science and making weapons and materials. Kaseki does not trust Senku at first, but the two form a bond over their love of building items and vehicles. The old crafter even admitted things got interesting when Senku came to the village.

When Kaseki and the others are petrified, Senku plans to revive Kaseki first, but is forced to change his plans after Kaseki is thrown into the ocean. Senku later revives Kaseki twice, so that he can help out and to free him from the prison of suspension.

### Ryusui Nanami

The child of the owner of Nanami Conglomerate. Despite hearing of his twisted personality from Minami, Senku revives him and is impressed by his accurate grasp on weather patterns.

When seeing Ryusui's entitled nature, Senku and Gen tag team to outwit the sailor, much to Ryusui's shock. Together, they team up to search for the Sagara Oil Fields that were previosuly discovered by Kohaku, and prepare for a journey in a search of the source of petrification.

Senku finds Ryusui amusing, since he has rebuilt currency and his advanced sailor knowledge. Ryusui also finds Senku to be more devious than him, showing he acknowledges his intellect.

There appears to be mutual respect between them, as Senku compliments his skills. Ryusui also mentions that had they met in the pre-petrification world, Ryusui would have hired Senku for his company.

When Ryūsui is petrified twice, Senku is the one who releases him. He also joined the others in adorning war paint (in reminiscent of his scars) to honor Senku, showing loyalty to him.

Although they briefly came to blows on the route to America, it was just a minor disagreement over technicalities, and soonn they were back on the same page, and soon later they were both in agreement on wanting to capture a fallen enemy airplane for themselves.

### Francois

Francois has deep respect for Senku for demonstrating his science during the "stone age", and mentioning what Ryusui said earlier before about having Senku working as an employee for Nanami Conglomerate.

Francois even knows about Senku's short marriage with Ruri. Once Senku was shot, Francois tended to Senku with bandages.

### Ukyo Saionji

A former SDF Navy member who served as a submarine operator.

Although initially enemies, due to their opposing Empires. Ukyo joins Senku after learning he and Yuzuriha are repairing the broken petrified humans.

He becomes one of the vital assets for the Kingdom of Science due to his perk of superhuman hearing. Ukyo joins Senku at being one of the Five Wise Generals.

### Nikki Hanada

During her alliance with Tsukasa, Senku was an enemy to Nikki at first. After hearing Lillian Weinberg's song through the communication device, she was easily swayed. When Senku promised to never let Lillian's legacy burn out, she claims to have fallen for him, much to Senku's discomfort.

After uniting the two kingdoms, Nikki has been helping with each task, and willingly assisted Senku with his plans on the ship, taking down enemies and ceasing any stupidity actions from Magma, Yo, and Mantle without question.

### Luna Wright

Senku first met her when she came to the Perseus after claiming to have escaped Xeno. Knowing she was a spy and needing information, he welcomed her board the Perseus. The others knew this was a ploy after he secretly made his intentions known . To that end, he made no qualms of hiding his desire to know about the enemy and showing off his intelligence when he used science to make soft serve ice cream to tempt her. It was through her, that he recalled Xeno was his former mentor. However, she has slowly become suspicious of him after hearing of his association with Xeno. After Senku is wounded from the aftershock of the shot, Luna starting to tend to his wounds.

Afterwards, she officially learns Senku is the scientist, while Senku asked her for helping him. Luna agreed to tend to his wounds but asked him to be her boyfriend, something that shocked him. Although Senku agreed, he likened the situation to a political marriage and seems more interested to the potential manpower she brings on the table, his friends speculate that he is using Luna to serve his own goals.

## Former Enemies

### Tsukasa Shishio

Since his depetrification, Senku was always wary of Tsukasa and his goals.
Because he is too strong, Senku has no other choice but to consider the possibility of Tsukasa and him not sharing the same principles. Tsukasa, however, deeply respects Senku and asks him to abandon science so that he doesn't have to kill him. Senku on the other hand, shares Taiju's opinion that while Tsukasa is inherently a good person, he is undeniably a murderer which needs to be stopped.

Tsukasa shares his regrets of not having talked to Senku 3700 years ago, saying that he may have become his very first friend, to which Senku replies "probably". The two remain enemies, as Tsukasa's troops frequently try and fail to destroy Ishigami village. However, Senku manages to order a ceasefire with Tsukasa upon revealing he could not only help de-petrify Tsukasa's sister, but also cure her of her brain dead vegetative state. When he does so, Tsukasa is grateful and promises not to harm Senku's group again. He even goes so far as to protect him from Hyoga's attack and trusts in Senku's promise to save him and cryogenically freeze him until he can.

After returning from Treasure Island, Senku used the Petrification Weapon to petrify Tsukasa and the latter was grateful. In reminiscent of his first revival, Tsukasa asked the situation and agreed to join Senku after the latter shrugged his past transgressions. Tsukasa recreated his scars, as a sign of loyalty.

Despite their ideological differences, Tsukasa and Senku respect one another for their intelligence and strength of will.

### Minami Hokutozai

Initially enemies at first, Minami still assisted Senku in finding a captain for their ship after he stated he needed her skills.

Minami is grateful for being gifted with a camera (even if it was in exchange for giving the last of her revival fluid for Francois, but also asked Senku to do another pose, but in a sexy way).

Even before Senku's group left for treasure island, she shows concern for everyone who was leaving for their voyage, and stating that it might be their last time together. Soon later tears of joy when everyone; including Senku; returned to the Kingdom of Science safely.

She was concerned for him after he was sniped by Stanley Snyder.

### Hyoga

Hyoga and Senku first meet as Senku scares Hyoga's men off with a gun, during the raid. Hyoga was impressed by Senku's skill, as Senku bravely asks Hyoga to tell Tsukasa that he is still alive, thus invalidating Gen's earlier claims. Hyoga became further impressed when Senku manages to create Japanese katanas for the Kingdom of Science in the second raid.

After the battle to claim the Miracle Cave ends in a truce, in exchange for reviving Mirai, Hyoga betrays Tsukasa by stabbing him in his lungs, with Senku following soon after. Thanks to Tsukasa and Senku's joint effort, Hyoga is finally defeated and has been imprisoned on the Perseus.

Later, during the attack of the Petrification Kingdom, Hyoga is revived as Senku's last-ditch effort. In the end, Hyoga decides to help Senku in battling Mozu, and trusted him enough to modify his spear, which allows him to defeat Mozu.

During the voyage to America, Senku decided to free Hyoga while he was still petrified because of Tsukasa. Senku was concerned about a potential hazard Hyoga may pose, giving Tsukasa the right to handle him. After he was freed, Senku gave him the option to join the Kingdom and Hyoga accepted after he was allowed to revive Mozu and Homura.

### Homura Momiji

He believes he can turn her over to their side despite her strong loyalty to Hyoga. He gives her cotton candy, claiming that he wants to sweeten her up, though Ruri suggests it is actually because she is a lonely girl in enemy territory and he wants to comfort her. Senku uses the blue jewel powder to track her. When she and Hyoga are captured, he keeps the both of them as prisoners rather than kill them.

When they set out on a voyage, to ensure they don't attack the village while he and the main team are gone and in case he needs extra muscle, he forcibly brings her and Hyoga along.

During the voyage to America, Senku allowed Hyoga to revive Homura and she became the navigator to the Perseus.

### Xeno Houston Wingfield

Senku regards him as an enemy because of the latter wanting to put him and his friends into servitude. It was for that reason, he refused to hand over the revival formula. Senku holds a trump card over Xeno, as the latter believes Taiju is the scientist and is unaware of Senku but Senku notes the same advantage goes for Xeno who has an arsenal of weapons.

When Luna states "Elegant" is the trademark word of Xeno, Senku realizes who he is and reveals Xeno was his mentor in the Pre-Petrification world.

Xeno and Senku met over the internet after Xeno saw Senku's theories on rocket science and decided to help him. The two met in person while Senku admired a monument of a ship, although it was silent both were aware who the other was. Regardless of their history, Xeno prioritize Senku's elimination, since he stood in the way of his plans but he survived in the end. Senku later spoke with his former mentor after the latter had his soldiers attack the Perseus and revealed he sent his best warrior after him too and Xeno captured by Tsukasa.

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. While captured Xeno watches Senku negotiate with Brody and is greatly shocked when Senku reveals the ingredients to the revival formula.

Despite technically being enemies, the pair realized they shared a common enemy in the Why-man.

### Stanley Snyder

Although the two have not yet met face-to-face, Senku and Stanley are enemies.

They indirectly first met when the kingdom of science was attacked by Stanley on the lake when they enter America but using his quick wit, Senku brought down the soldier's plane. Stanley was impressed by this noting that the enemy had a science user like his side.

Stanley was tasked with assassinating Senku, nearly succeeding had the young scientist not create a bulletproof vest.

Stanley later expressed ire to learn of Senku's survival and he kidnapped Xeno. To make up for his failure, Stanley pursued Senku and his group to South America after they fled on a boat.

Before crossing to the Amazon rainforest, the pair narrowly met but Senku left on a motorcycle while taunting an infuriated Stanley with a smile.

Stanley later ordered his unit to open fire on the science grade and leave no survivors in order to rescue Xeno. With most of its members laying dying, Senku was forced to utilize a last ditch effort by having his allies in America activate the petrification weapon and petrified a whole world. Stanley was shocked by this action and realize that the science brigade will revive soon and leave him petrified. Having come to respect Senku, Stanley simply took one last smoke and complemented the young scientist on his endeavors.

### Why-man

Why-man is the nickname given to a mysterious individual who they received a Morse code message from. Senku believes them to be the individual responsible for the petrification incident, or at least related to it somehow. One of the reasons Senku has built the Perseus is to find out who Why-man is.

According to Ukyo, they sound alike. Senku was intrigued by this, even more so to hear that this enigmatic foe is on the moon and resolves to pursue them for answers.

## Enemies

### Ibara

Ibara is the former leader of the Petrification Kingdom and formerly, the one who held Medusa, the source of Petrification. He petrified many of Senku's allies. With help from Ryusui, Senku petrified Ibara.

## References

1. ↑ Dr. Stone Manga: Chapter 10, Page Byakuya helps Senku.
2. ↑ Dr. Stone Manga: Chapter 45
3. ↑ Dr. Stone Manga: Chapter 140
4. ↑ Dr. Stone Manga: Chapter 232
5. ↑ Dr. Stone Manga: Chapter 9, Page Senku saves Yuzuriha.
6. ↑ Dr. Stone Manga: Chapter 102
7. ↑ 7.0 7.1 Dr. Stone Manga: Chapter 154
8. ↑ 8.0 8.1 Dr. Stone Manga: Chapter 155
9. ↑ Dr. Stone Manga: Chapter 107
10. ↑ Dr. Stone Manga: Chapter 138
11. ↑ Dr. Stone Manga: Chapter 18, Page 14
12. ↑ Dr. Stone Manga: Chapter 19
13. ↑ Dr. Stone Manga: Chapter 31
14. ↑ Dr. Stone Manga: Chapter 77
15. ↑ 15.0 15.1 Dr. Stone Manga: Chapter 160
16. ↑ Dr. Stone Manga: Chapter 217
17. ↑ Dr. Stone Manga: Chapter 57
18. ↑ Dr. Stone Manga: Chapter 56, Page Gen reveals Senku's Birth date.
19. ↑ Dr. Stone Manga: Chapter 85
20. ↑ Dr. Stone Manga: Chapter 146
21. ↑ 21.0 21.1 21.2 Dr. Stone Manga: Chapter 150
22. ↑ Dr. Stone Manga: Chapter 162
23. ↑ Dr. Stone Manga: Chapter 163
24. ↑ Dr. Stone Manga: Chapter 5
25. ↑ Dr. Stone Manga: Chapter 141, Page Senku revives Tsukasa.
26. ↑ Dr. Stone Manga: Chapter 84
27. ↑ Dr. Stone Manga: Chapter 93
28. ↑ Dr. Stone Manga: Chapter 130
29. ↑ Dr. Stone Manga: Chapter 132
30. ↑ Dr. Stone Manga: Chapter 146, Page Senku revives Hyoga.
31. ↑ Dr. Stone Manga: Chapter 146, Page Senku permits Homura's return.
32. ↑ Dr. Stone Manga: Chapter 152
33. ↑ Dr. Stone Manga: Chapter 155, Page Senku reveals Xeno is his mentor.
34. ↑ Dr. Stone Manga: Chapter 156
35. ↑ Dr. Stone Manga: Chapter 168
36. ↑ Dr. Stone Manga: Chapter 170
37. ↑ Dr. Stone Manga: Chapter 149
38. ↑ Dr. Stone Manga: Chapter 176
39. ↑ Dr. Stone Manga: Chapter 193
40. ↑ Dr. Stone Manga: Chapter 138, Pages Senku hears the Why-man.
41. ↑ Dr. Stone Manga: Chapter 139, Page Senku decides to face his foe.