Princess Nagiko Kiyohara, a historical figure from the Heian Period, resided in what would become Kokuga, the capital of Suō Province. A lonely princess who relocated from a larger city to this rural capital, she endured isolation and a deep yearning for friendship.

Her tale is uncovered and envisioned by a modern child, Shinko Aoki, through her grandfather's stories. In these imaginings, Princess Nagiko is barred from friendship with local village girls, intensifying her solitude. Her narrative parallels the modern story of Kiiko Shimazu, a transferred student who also feels like an outsider and grieves a lost parent.

A pivotal moment arises when Kiiko Shimazu, through Shinko's imagination, mentally travels back in time and briefly becomes the princess. In this instance, Nagiko assists a local girl and at last forges a friendship, resolving her loneliness. This connection across time links past and present through themes of isolation and the universal need for companionship.

Her story culminates with Princess Nagiko and her friend seated on a stone, enjoying the friendship made possible by the actions and imaginations of Shinko and Kiiko in the modern era. Her narrative acts as a historical echo of the contemporary characters' experiences, highlighting timeless challenges of adapting to new surroundings and overcoming loneliness through human connection.