The fourth sovereign daughter of the Principality of Rain, Nike, has been betrothed to the Sun King, Livius I. After a long journey, she arrives in his Sun Kingdom, only to be shocked by its prosperity. She decides to wander the kingdom herself to see what it's like, when two men appear before her...

Nike's busy life as wife of the Sun King is interrupted by an urgent message from the Principality of Rain. Nike's grandmother, Tohara, has collapsed, and she wants to see her granddaughter. Livi notices Nike's concern for her grandmother, and decides to journey with her to the Principality of Rain.