On a planet far from Earth, there is a kingdom full of smiling faces. Princess Yuuki is 12 years old, and about to enter a sensitive age in a person's life. Everyday, she cries, laughs, and sometimes, her heart throbs with excitement. All the while, she lives merrily in the royal palace.

Filling her days are her loyal vassals: her tutor Reira, Izana who assists in political affairs, the leader of the chivalry Harold … and then there is her childhood friend and aide Joshua.

"Yuuki! If you have spirit and guts, you can do anything!"

"…No, not this again! Joshua, be nobler!"

Stella is 17 years old and a capable, reserved soldier. However, she is always smiling ... for smiling is essential to living.

This is a story of two girls born on distant planets.