Kaseki (カセキ) is an old man artisan and an expert craftsman, who resides in the village.
Kaseki is a bald, short and muscular old man with a large white beard. Every time he was fired up, however, his clothes always ripped apart.
Kaseki is an honest old man who takes prides in his work as an artisan. He remains civil on most occasions unless provoked.
He is shown to be untrusting of outsiders, at first refusing to help Senku. He only agreed after being tempted by the glass that Senku was able to make (but not form well due to lack of technique). Due to his love of crafting, he immediately developed interest and learned instantly how to properly form the glass into flasks for Senku, despite having never once seen glass or been taught any technique. As a craftsman, he is a genius surpassing even modern craftsmen, managing to help Senku make several of the flasks and other things he needs. He even learns to do blacksmithing which only further helps Senku's goals. Despite continually helping Senku during the Ruri illness arc, he admits he still didn't fully trust him when even Kinro and Ginro had started to trust him. It takes a while before he fully becomes loyal to Senku as an ally and acknowledges him as a close friend. He admits that when he was young due to his village valuing strength he was not looked upon well by his tribe as he focused more on crafting and couldn't relate to others. He is genuinely moved when Chrome refers to Senku, Kaseki, and himself as close friends. When Senku embarks on his labor intensive projects, he becomes excited and his clothes rip off changing his form from a small meek old man to a powerful muscular old man.
As the oldest in Senku's main group of friends, he tends to be rather wise, imparting wisdom on others and is not ashamed or afraid to admit his shortcomings and weaknesses.
Despite his pride and honesty, Kaseki has proven to have quite the perverted side of him. Two examples is how he seeks praise for his work, specifically from women and almost immediately concluding Chrome tying him up as a form of "bondage" antics.
Abilities and Skills
Kaseki is an artisan with sixty years of experience under his belt. He craftsman much of the architecture of the village including the drawbridges.
He also made the shield for Kohaku's father Kokuyo when he won the village games, which was given to Kohaku as a gift.
Along with Chrome, Kaseki was pretty much the only one in Ishigami Village with any real scientific knowledge. Kaseki is artisan who is very proficient at what he does. Kaseki has shown to complete tasks that even Senku could not, like shaping glass.
Kaseki is also a fast learner as seen when he easily learned how to make Japanese swords.
Kaseki's physical abilities are high, because of his very muscular build. Kaseki might have a very built body, but he has minimal skill in combat.
Kaseki was able to construct a complex structure, including a vial that has high complexity. Most of Senku's technology was created by him including katana and steam engine.
Senku admits Kaseki's building skills surpass his own.
Just like the rest of the village, Kaseki is a primitive human. Kaseki is also a descendant of Byakuya Ishigami and his crew. In his youth Kaseki loved crafting all manner of creation however that made the other villagers look at him with disdain in response Kaseki built the Bridges that connect the Ishigami village and started creating the shields for the tribe.
PlotKaseki is introduced as one of the inhabitants of Ishigami Village. Upon hearing rumors of Senku, a boy from outside the village, he found it curious.
Kingdom of Science Arc
In order to create glass vessel, Chrome solicited Kaseki's assistance, tying him and dragging him back to Senku. The old man at first refused to help them due to his treatment but became intrigued by their attempts at glass work. When Senku and Chrome attempted to amateurishly blow glass and fail it infuriated him to the point that he broke through his bonds and took over the process.
He later aids in making Gas Masks. He inspired Ginrou to be less cowardly and this caused him to save Chrome from the acid.
Vs. Hyoga Arc
After Senku became the village head, Kaseki helped in the advancement of their people in his ways. For the village's advancement, Senku along with Kaseki start forging Japanese swords for all their warriors. Senku explains how the task of making these swords is very difficult and tedious, but Kaseki easily learns it. Kaseki was able to make enough swords to equip every capable fighter in the village. 
Kaseki along with Chrome spent three days to build a water wheel/mill, but to their surprise Senku already knew about this invention. The water wheel was then used along with the cotton candy tool to create an electrical water powered generator.
Age of Exploration Arc
Kaseki aids in build Cameras and a hot air balloon. Kaseki aids in building the Perseus and finishes it in a year. He joins the Perseus as part of the crew.
Treasure Island Arc
Upon reaching Treasure Island he is among those that are petrified by Ibara and his forces. Kaseki's body is shattered and tossed into the sea by Ibara and his men.
Kaseki is on good terms with Chrome due to their similar interests in science, craftsmanship and material gathering. The two often work together on projects like glass and vehicles.
- His name Kaseki is the Japanese word for Fossil the remains or impression of a prehistoric plant or animal embedded in rock and preserved in petrified form.
- The unique thing is every time he fires up, his clothes always ripped apart regardless it was his own clothes or high-quality clothes made by Yuzuriha.
- He ranked 9th in the 1st popularity poll.
- ↑ Dr. Stone Manga; Volume 4, Q&A Section
- ↑ Chapter 99
- ↑ 3.0 3.1 Dr. Stone Manga: Chapter 48
- ↑ Dr. Stone Manga: Chapter 29
- ↑ Dr. Stone Manga: Chapter 52
|Male||Taiju Oki • Senku Ishigami • Gen Asagiri • Chrome • Kaseki • Kinro • Ginro • Magma • Ryusui Nanami|
|Female||Yuzuriha Ogawa • Ruri • Kohaku • Suika • Nikki • Minami|
|Male||Chrome • Ginro • Jasper • Kaseki • Kokuyo • Kinro • Magma • Soyuz • Tetsuken|
|Female||Garnet • Kohaku • Ruby • Ruri • Sapphire • Suika • Shirogane • Turquoise|