Meiji 34 (1901), Youko, the youngest daughter of Takatsukasa—one of the five regent houses, was only four years old when she invented a method to synthesize white thread from chemicals. This thread was known as “Nylon 66”, a substance that should have been discovered in America. This isn’t surprising considering Takatsukasa Youko was a macromolecular chemist that lived in the Reiwa era, more than 120 years in the future, and kept her memories as she reincarnated as a girl. This is an era where the world macromolecule does not exist and a story of her hard struggle to change Japan’s history.