Koutarou Aoki, Shinko's grandfather and a former teacher, resides with her family in 1950s rural Yamaguchi Prefecture. His profound knowledge of local history, especially the area's time as the ancient capital of Suō province during the Heian period, fuels Shinko's imaginative explorations. He recounts detailed tales of Princess Nagiko Kiyohara, who inhabited the same location a millennium prior, directly sparking Shinko's vivid daydreams and her ability to envision the historical past. His storytelling bridges Shinko's experiences with the ancient princess's life, fostering her curiosity and connection to the land's heritage. His passing during the winter leads Shinko's family to relocate to the city near her father's workplace.