Chrome

Chrome is the village's self-taught scientist before Senkuu ever arrives, though he thinks of his experiments as sorcery rather than chemistry. Once he meets Senkuu, he realizes what he has actually been doing all along and jumps at the chance to learn real science. He becomes Senkuu's closest partner in rebuilding civilization and takes a leading role in the Craftsmanship and Development Team, eventually earning a place among the Five Wise Generals.

Chrome's defining trait is his curiosity. He gets excited about almost everything new, from rocks to chemical reactions, and that excitement pushes him to keep experimenting even when he fails. His collection of unusual stones, which he once thought held magic, becomes genuinely useful once Senkuu shows him how to read them scientifically.

His drive to learn science in the first place came from wanting to cure Ruri, the village priestess and Kohaku's older sister, of her illness. That goal stays with him through the whole story, and the two eventually marry after years of him working toward it. Chrome's growth, from a village outsider dabbling in make-believe magic to one of the smartest people helping rebuild the modern world, mirrors the show's larger message that curiosity and persistence matter more than natural talent.