On a planet far away from Earth, there is a kingdom full of smiles. Princess Yuki, 12 years old, is entering a sentimental age. She spends her days happily in the palace, crying, laughing, and sometimes feeling moved...? Her loyal retainers add color to her days. Leila, who is in charge of education, Izana, who assists in government affairs, Harold, the leader of the Knights, and... Joshua, her childhood sweetheart and follower. "Yuki! As long as you have the spirit and perseverance, you can do anything!" "...Really. That again~!? Joshua, you have to act more like a noble!" Stella, 17 years old, is a capable and calm soldier. She will never lose her smile...because a smile is indispensable for survival. This is the story of two girls born on a distant planet.