"I am a technology kid, who's excited by mecha, space and Doraemon! I will save all of humanity, without exception, with the power of science!"
— Senku Ishigami, Chapter 4
Senku Ishigami (
As the first-prize champion in the Grand Bout, Senku currently holds the title of Village Chief in Ishigami Village, where he is widely regarded as a legend thanks to the late Byakuya’s influence in the founding of Ishigami Village.
Senku is the de facto leader of the Kingdom of Science. Later, as a member of the Five Wise Generals, Senku provides the ideas and initative for their large scale plans; he consults with Chrome, Gen, Ukyo, and Ryusui before taking action.
Senku is a slim, yet reasonably toned young man of average height with white (light green in the anime,) brush-like hair that spikes up, with two locks of hair that drape over his face, and sharp red eyes. Kohaku admitted that he looks like a "lady killer" to her, implying he is handsome. Luna has also expressed an attraction to Senku.
Senku's stone markings are two, symmetrical diagonal lines on top of his inner eyebrows.
Pre-Stone World, Senku wore a typical school uniform with a lab coat over it. After waking up in the Stone World, he switched to wearing animal skin clothing in a rudimentary manner. After Yuzuriha's de-petrification, these clothes patched up and are generally more presentable. He has Albert Einstein's mass–energy equivalence formula (E = mc2) written in his own blood across the breast of his shirt.
During Minami's photoshoot with Senku for the hot air balloon launch event, Senku wore modern outfits fashioned by Yuzuriha.
Senku is a straight-forward, confident and highly logical individual who can come off as arrogant. Even so, Senku's borderline-overconfidence does not cloud his judgment, as he is often backed up by a vast underlying knowledge of science. Senku never belittles those who are less knowledgeable than him. Rather, he encourages and inspires everyone around him to do better. Because of his charisma and caring nature, people tend to gather around him, supporters and allies alike. At times when he is excited over a creation or at the discovery of something new, Senku can act over-the top, showing exaggerated emotions. Despite his usual appearance brimming with confidence and determination, Senku is not above berating himself if he does miss important information, such as when Kohaku pointed out the precession of the North Star that Senku had overlooked because he had not internalized the full effects of the many years that he was petrified. 
Although Senku has a strong sense of justice, he often bends the rules, withholds information, and manipulates others to get what he wants, but if only for the better of his allies. He often acts as if he builds inventions and uses people for his own interest, while actually creating for the betterment of others. Examples of this behavior include glasses for Suika and others and the automobile for Ishigami Village's elderly. Beneath Senku's outward arrogance and manipulative actions lies a genuinely selfless and kind heart. This is proven time and time again, particularly when Senku mourns his adoptive father's death. During their decisive battle, Tsukasa notes that despite Senku's apparent cold rationale, his greatest weakness is his inability to abandon his friends, having witnessed his kindness firsthand with Yuzuriha taken hostage.
Unlike Taiju, Senku seems averse to the idea of romance. He seemed disturbed when Kohaku worded her praise for him strangely, claiming she had "fallen for him." In addition, he immediately divorced Ruri, in the few seconds of their marriage. He was also completely unaffected by Amaryllis' attempts to charm him, much to her chagrin. He believes a brain filled with love is most illogical, but he does support the romantic endeavors of his friends, such as Taiju's relationship with Yuzuriha, and Chrome's relationship with Ruri. Despite all this, Gen believes that one day, after all the conflict is over, Senku may consider the idea of romance.
What Senku lacks in physical ability, he more than makes up for with his determination and persistence. He counted the time he was petrified to the last second for nearly 4 millennia and willingly faced death by Tsukasa's hand without being fazed, refusing to back down and sacrifice either Yuzuriha or the continued advancement of science for his own personal safety. Senku also defeats Ibara with his quick thinking and help from Ryusui Nanami. Senku is simply someone who refuses to give up on a task no matter how arduous.
Abilities and Skills
Genius Intelligence: Senku Ishigami is a genius with an encyclopedic knowledge of all things scientific. He is well versed in chemistry, physics, engineering, geology, biology and mathematics. Senku is able to easily create various useful tools and gadgets, medicine, and most notably, the de-petrification elixir, despite the limited materials of the Stone World. Tsukasa calls him "the sharpest, most intelligent man in the world". In addition to his scientific knowledge, Senku also possesses great resourcefulness and an analytical mind, seemingly never having a shortage of options at his disposal. For whatever he lacks, he has an ally who can offer their strength. He also possesses great mental fortitude, able to think quickly on his feet and keep his cool in the most dire of situations. Out of the current active characters, his mental assets are rivaled only by his former mentor, Dr. Xeno.
- Craftsmanship: As a child, he designed and built a functioning miniature rocket ship, alongside many other advanced and experimental machines. However, Senku doesn't compare to a master craftsman like Kaseki, in terms of building skills, as Kaseki has far more experience than him.
- Tactical intelligence: In addition to his scientific intelligence, he appears to have some skill as a strategist. He managed to coordinate the villagers and even some of Tsukasa's army whom he converts to his side in an effective bloodless war against Tsukasa's Empire of Might. Similarly, he manages to have Kohaku, Ginro, and Amaryllis infiltrate the chief of Treasure Island's harem as spies and manages to communicate with Kohaku and develop a strategy to cleverly gather the scattered petrified pieces of his friends along with the precious stones from the Soyuz chamber.
- Eidetic memory: Senku remembers every compound and sequence of his inventions. He has never once been wrong in the making of tools for the Kingdom of Science, and has an enormous amount of knowledge in aformentioned science fields.
- Charisma: Though arrogant and eccentric, Senku seems to have a good understanding of people and how they think. He uses his many creations to charm those who were suspicious of him (like ramen, glasses, and medicine) to slowly warm up to around him. Senku is also a capable leader, who is good with his words, able to motivate and lead the villagers into an effective army against Tsukasa's Empire of Might. He has personally gained the loyalty and respect of his allies (and enemies) through his hard work and determination.
- Linguistic Proficiency: Senku seems to be fluent in both Japanese and English. He understood Ukyo and Gen's while they were speaking English through the buried phone in order to conceal their conversation from the others present. He was able to speak to understand the discussion between Taiju and Dr. Xeno with no problems. He understood and communicated with Dr. Brody with no problem.
Low physical prowess: Senku is below average in terms of physical ability, lacking physical strength. He was unable to hold Homura, a petite woman shorter than 5 feet, after managing to grab hold of her. He also admits that he won't stand a chance against someone as strong as Kohaku in a fight (although it's not really a fair comparison, given her strength and her status as a warrior). In a bonus chapter, Kohaku gives a small description on the physical abilities of the main characters. Senku is at the bottom at around 3 points, Chrome at 5, Ginro at 100, Kinro at 500, and Kohaku herself at 1000. Similarly, Senku has poor stamina, and tends to get physically exhausted rather quickly. He is also very vulnerable to hypothermia, only being able to withstand cold water for a short amount of time.
Average craftsmanship: While not bad in terms of craftsmanship, he lacks the natural talent in it. It took him several months to learn how to do pottery, and even then, it could only be considered decent. He has also failed miserably at making glassware, and for more detailed and intricate objects, requires expert craftsmen like Kaseki to make them. He also requires Yuzuriha to piece together the broken stone statues as he lacks her talent and precision.
Lack of cooking skills: While not a weakness per se, he is not an exceptional cook. He is shown to know how to cook, but lacks experience and quality ingredients. While he knows the process of how to make food, most of the time, the more complicated food does not taste good. While he was able to make cotton candy and cola, more complicated foods, such as wine, ramen, and bread prove to be terrible tasting. While in the ramen's case, part of it is due to not having the exact ingredients (he uses foxtail to make flour instead of wheat). When he tries to create bread with all of the proper ingredients on hand for the first time, it comes out so horrible that no modern person is capable of eating it (though the Ishigami Village tribe loves it because they have only ever eaten fish and have never tried bread before).
Bad luck: Throughout the series, despite his high intelligence and ability to overcome obstacles, he tends to run into trouble often due to his horrific luck. Gen, at one point, quips to Senku (while they are trying to make gunpowder to stop Tsukasa's army and fail) that Senku always has crappy luck. In the Petrifaction arc, where he goes to Treasure Island, after all their resources and options have been exhausted as he and the Kingdom of Science are cornered by Ibara, Mozu, and their army, Senku is even forced to use his worst trump card: reviving Hyoga (a rather unpredictable and cruel man willing to manipulate and kill anyone who gets in his way) to have a fighting chance against Ibara and Mozu despite the strong possibility Hyoga will immediately overpower the Kingdom of Science and/or learn of the petrification device afterwards. Later on, Ibara uses the petrifaction device to petrify everyone but himself. When detailing travel by Vikings, a storm hits but they still reach America, due to Chrome. While commencing their exploration of United States, the crew is attacked by alligators as Gen once again makes a remark about how Senku's luck is non-existent and every one of his hypotheses about the worst-case scenario usually turn out to be true.
- Senku's name is composed of "sen" (千 thousand) and "kū" (空 sky) to create Senkū (Thousand Sky), which is homophonous to
先 駆, meaning "pioneer". Ishigami is composed of "ishi" (石 stone) and "kami" (神 god) to create Ishigami (Stone God).
- Senku shares a motif with Taiju and Yuzuriha in that his name contains "kū" (空 sky) in his name, which correlates to the theme of "land, sea, and sky".
- Senku has been ranked 1st place in the 1st and 2nd Character Popularity Polls.
- There have been women who have shown signs of attraction to him:
- Kohaku claims to have fallen for him when they first meet, leaving him disturbed. Though she clarifies that she means it in a platonic manner, she admits in chapter 22 that he looks like "lady killer" to her.
- Ruby states that she is interested in a man who will dote on her and she is so impressed by the ramen that Senku makes that she asks what his type is.
- He marries Ruri, but divorces her almost immediately.
- In chapter 51, when Senku asks Gen about Homura, to which Ginro, Shovel, and the Sisters assume he's asking about her romantically. He later rebuffs any attempts to take advantage of Homura after catching her.
- After Senku promises Nikki that he will protect Lillian Weinberg's last recorded song, Nikki also claims she could fall for him, something he casually shrugs off.
- He was immune to Amaryllis' charms.
- He is kissed by Kohaku and reacted indifferently.
- He charms Luna to get information out of her and leaves her with a crush on him, then later Luna asks if he'll be her boyfriend.  The crew later comment that Senku has no interest in romance.
- He states Doraemon is what inspired him to become a scientist.
- He demonstrates a love for video games, making references to Super Mario Bros, Civilization, Dragon Quest, and Monster Hunter (Monster Hunter having a particular shout out in chapter 63).
- He has three main catchphrases: he claims "10 billion percent" when he is certain of something, "1 mm" when he claims how impossible something is, and "This is Exhilarating ("Get Excited" in the English dub)" when a new development occurs or he manages to further his scientific developments.
- A recurring gag involves Senku's previous marriage and divorce being referenced:
- When Hyoga approaches Senku to form a partnership, Senku tries to brush it off by asking if it was his version of an awkward love confession and then states how he is married (and then corrects that he is now divorced).
- When Amaryllis asks about Chrome's relationship with Ruri, Francois points out that Ruri was once married to Senku before Senku divorced her, shocking Taiju and Amaryllis.
- When Luna asks Francois about dating Senku, Kinro brings up how Senku is a divorcé, to her shock.
- He shares traits with Yoichi Hiruma from Riichiro Inagaki's previous series Eyeshield 21.
- Grinning when conducting the best situation to meet his ends.
- High intelligence, photographic memory, and cunning.
- Proficient with arithmetic, being able to calculate long periods of time down to the last second.
- Senku's bowel movements prior to petrification were pretty regular.
- Senku's name was originally going to be "Gaku" and use the kanji for "study" (学), but was changed because Inagaki found it felt too academic.
|Male||Chrome • Gen Asagiri • Ginro • Hyoga • Kaseki • Kinro • Kokuyo • Magma • Matsukaze • Mozu • Ryusui Nanami • Senku Ishigami • Taiju Oki • Tsukasa Shishio • Yo Uei|
|Female||Homura Momiji • Kirisame • Kohaku • Minami Hokutozai • Nikki Hanada • Ruri • Suika • Yuzuriha Ogawa|
|Male||Dr. Brody • Byakuya Ishigami • Carlos Barrios • Gen Asagiri • Hyoga • Joel • Leonard • Max Adams • Ryusui Nanami • Senku Ishigami • Shamil Volkov • Stanley Snyder • Taiju Oki • Tetsuya Kinomoto • Tsukasa Shishio • Ukyo Saionji • Xeno Houston Wingfield • Yakov Nikitin • Yo Uei|
|Female||Charlotte • Chelsea • Connie Lee • Darya Nikitina • Homura Momiji • Lillian Weinberg • Luna Wright • Maya Biggs • Minami Hokutozai • Mirai Shishio • Nikki Hanada • Yuzuriha Ogawa|