Kaseki, an elderly master artisan of Ishigami Village, is celebrated for his unparalleled craftsmanship and tireless dedication. Over five decades, he shaped the village’s foundations, constructing bridges, shields, and vital structures long before allying with Senku. His mastery of glass, metal, and stone springs from an unyielding passion for creation, though his unconventional pursuits once distanced him from villagers who dismissed his inventive spirit. He presents as a diminutive, bald figure with a sweeping white beard and thick eyebrows, typically clad in a simple brown tunic. When inspired, his fervor shatters this modest exterior—literally bursting through his garments to unveil a powerfully built frame honed by labor and briefly revitalized by petrification’s effects. Pride in his work intertwines with a humorous craving for admiration, especially from women. Initially cautious, he grows inseparable from Senku and Chrome, embracing their scientific zeal. Though confident in his skills, he openly acknowledges gaps in his knowledge, offering sage counsel while humbly accepting guidance. His emotional transparency surfaces in moments like tearfully lamenting perceived exclusion from Senku and Chrome’s bond, only to realize his deep kinship with both. His ingenuity proves indispensable across critical endeavors: crafting gas masks for medical missions, engineering tournament strategies, forging blades for combat, and assembling complex inventions like hydroelectric generators, vacuum-tube communicators, and armored steam vehicles. After petrification and revival on Treasure Island, he repairs the Perseus ship and co-creates surveillance drones. Later explorations see him modifying aircraft, constructing balloons, and shaping a massive terrestrial globe, his wonder at human innovation never waning. Kaseki’s journey mirrors themes of connection—transitioning from solitary artisan to collaborative pioneer, merging ancestral techniques with cutting-edge science. His lineage as a descendant of Byakuya’s crew echoes a heritage of resilience, anchoring his loyalty to the Kingdom of Science’s mission. Despite repeated petrification setbacks, he persists, channeling timeless craftsmanship into humanity’s renewed progress.