Tokyo's most disciplined software engineer loses his job to AI, and then everything else, until a code editor opens in the night sky holding one unreferenced function: reset(). He runs it. Reborn as Erias in a world ruled by magic, he discovers the truth as a baby: magic is programming, and every mage alive writes legacy code. Erias wants something for the first time in two lives: to out-engineer a civilization of wizards and maybe, accidentally, learn how to have a family, friends, and a life.