There is a kingdom full of happy faces on a planet far away from Earth. Princess Yuuki is 12 years old and approaching a critical juncture in her life. Every day, she tears, laughs, and her heart flutters with joy. Meanwhile, she lives happily in the royal castle. Her days are filled with her devoted vassals: her instructor Reira, Izana, who aids in political matters, Harold, the captain of the chivalry... and then there's Joshua, her childhood friend and aide. "Yuuki, you can achieve anything if you have spirit and guts!" "...Not again, Joshua! Be nobler!" Stella is a skilled, reserved soldier who is 17 years old. She, on the other hand, is always smiling... Because it is necessary to smile in order to live. This is the case.