Biologically speaking, no he is not. Nobody could have guessed that Senku Ishigima is not related to his father, Byakuya, by blood. The two share so many similarities rather than differences that makes it harder to doubt their relationship. From the looks to their intelligence, some details are too uncanny. However, the truth is out, and even a little bit of information regarding Senku’s biological parents have been shared.

Little is known about the relationship between Senku and his father, Byakuya, in Dr. Stone. This is due to the reasons that the story immediately starts after Senku got de-petrified and flashbacks did not dwell much on their father-son relationship. However, it can be said that Senku’s success in becoming one of the greatest scientists was heavily influenced by none other than his father. Byakuya Ishigami may not be Senku’s biological father. But, he has been more of a father than anyone is to the young scientist.
Who is Byakuya Ishigami?
A supportive father, a wise leader, and a great friend. These are just some of the words that would describe Byakuya Ishigami. Before the petrification that made everyone a stone happened, Byakuya was like most of us. He was just the usual caring father who worked part-time as a professor at the university. His keen interest in learning, maybe not as much as Senku, but still, some of it has awakened Senku’s love for learning as well.

Unlike Senku, Byakuya is more carefree and fun. We always see him smiling, laughing, and making the mood lighter for everyone. He has always aspired to be an astronaut but failed due to his inability to swim. Even with this, he did not let it get to him and instead remained a good father to his adoptive son. Fortunately, his path to becoming an astronaut did not end yet after his first failure.
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After officially becoming one of the astronauts, Byakuya joined the team as one of the people chosen to travel to space. Together with the other chosen scientist, Byakuya resides in the Internation Space Station in space where he was when the mass petrification happened on Earth.
His charming and kind-hearted personality allowed him to build a bond of friendship in space. He found a family with the other astronauts namely Lillian Weinberg, Connie Lee, Shamil Volkov, Darya Nikitina, and Yakov Nikitin. Despite belonging to different races, Byakuya’s friendly personality resulted in all of them sharing stories, food, and listening to Lillian singing.

These were also the same people who stood beside Byakuya when they all decided to return to Earth. Without a single sign of humanity, Byakuya decided to take on the role as the leader of their group and live on despite what happened. Without any idea of what was happening and their lack of resources, Byakuya and the others rebuilt a village where they began their journey in the Stone World.
Byakuya Ishigami knows by heart that he had lost for the meantime his son, his friends, and his colleagues. His determination stood as his will to handle the pain due to the loss of the seven billion victims of the petrification. This shows that his bravery is much bigger than his fears in life. Byakuya founded the Ishigami Village and never lose hope that one day his son, Senku, will find his way to this village.
In Dr. Stone seasons one and two, there is no sign that could incorporate that Byakuya had a wife or that Senku had a mother figure in his life. However, the key for humanity to never be extinct is to procreate, that is basically what the astronauts did.

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The six astronauts found love from one of their crew members. It is assumed that Byakuya found his other half through the famous singer, Lillian. Lillian became Byakuya’s closest companion during their time on Treasure Island. Also, it is assumed that the two eventually married and had kids together. This leads to Riri and Kohaku being one of their descendants.
To further help his descendants in surviving the Stone World, Byakuya again utilized his intellect and earnest wish for humanity to get through this obstacle by writing the one hundred stories. The Hundred Stories was a tale that contained preserved knowledge about the world before the petrification happened.

This knowledge was written for the succeeding generation that truly helped them in surviving in the wildlife. Byakuya Ishigami’s compassion, hope, bravery, and adaptability made him a natural leader allowing him to have one of the most crucial roles in humanity’s survival in Dr. Stone.
A Closer Look at Senku and Byakuya’s Father-Son Relationship
Byakuya Ishigami is perceived in the series as a loving and caring father to Senku. Although, their relationship isn’t that lovey-dovey. They sure know how to express their love for one another without the need to say it. As they say, actions speak louder than words and Byakuya certainly abides by that phrase in showing his deep love for his son.
There is not much information about the real identity of Senku’s biological parents. However, it is believed that his biological father is a close friend of Byakuya Ishigami. Basically, Byakuya legally adopted his friend’s son due to still for an unknown reason. There is no confirmation of whether the man is alive or dead. Even Senku doesn’t take much interest in finding out more about his real parents. This can be due to the fact that his adoptive father, Byakuya, has already shown the love and sacrifices that a father must give to his child, and for him, that is enough.
Sold His Car Without Hesitations for Senku
Byakuya and Senku don’t have a luxurious life. Instead, they seem to just have a simple life with Byakuya being an average salaryman. However, he is a father and will go out of his way just to show support to his son. A car is very important to an adult’s life. Not only does having a vehicle help them to travel easier, but it also represents that you have a more stable life by being able to afford one.
But, this was all nothing for Byakuya when he realized the passion of his son. Instead of playing outside or playing video games, Senku always spent most of his time reading and trying out things. Therefore, his father encourage him to pursue his love for science and even made a sacrifice for it.

Byakuya took the initiative in selling his car to a second-hand car dealership just for his only son to have all the scientific equipment and resources he need. He became his son’s own Santa Claus. This big gesture from Byakuya was much appreciated by Senku and from that day he began to take science more seriously than before.
Senku’s Scientific Invention That Made Him an Astronaut
Something that makes Byakuya and Senku different is that the son is more immersed in the whole concept of science compared to his father. However, their dream is clearly the same and that is for them to someday travel to space. After ten years since Byakuya’s last attempt to be an astronaut, he qualified again as one of the hopeful candidates. When his son found this out through the website he instantly went on to build something that will help his father in increasing his chances to get accepted.

He built an electrode training suit for his father’s swimming examination. Senku had always invented things for himself which is why the suit was a huge thing for Byakuya. It motivated him to even try harder in order to not let his son’s effort go to waste. He believed that becoming an astronaut and working for science is a way for him to repay his son’s kindness and love.
A Thousand Years Later: Byakuya’s 14th Tale in the Hundred Stories
Senku Ishigami meeting Kohaku and becoming the village chief seems to be more of a destiny rather than a mere coincidence. I mean, if it was Senku talking he would have guessed one billion percent that he was meant to find the village one way or another. Why? Because Byakuya Ishigami is the founder of the said village and the one who named it Ishigami Village.

Byakuya did not only name the village after them and wrote the one hundred stories just to preserve the knowledge of the modern era. But, in tale number 14 of the hundred stories is a clue that he knew Senku would only know. In his tomb, Byakuya left a record with a coded message for his only son. As a father, he let out all the words that he wanted to tell his son. Byakuya got to express how much he loves him without saying it out loud. Thousands of years may have passed but Senku was always in his father’s mind and the coded message is a solid proof of that.