Sakura is the granddaughter of a mysterious moon princess who slew demons with her Blood Cherry Blossom sword. All her life Sakura has been forbidden to look at the full moon without knowing why. Then one night, unhappy over her impending marriage, Sakura gazes up at the moon, only to see a demon attacking her...

Princess Sakura has been engaged to Prince Oura since birth. Aoba, an emissary from the court, has come to accompany her move to the capital for her upcoming nuptials. Taking a dislike to Aoba and wanting to escape a life arranged by others, Sakura runs away--and finds she's caught up to her true destiny.