Kaseki

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. 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. 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.