Ten letters

Remorse for a mistake that seemed to be right at first is the worst feeling in the world. As the truth is revealed when regrets are no use.
Yeonhee's life is dedicated by her miserable fate with her beloved jeon so, whose heart beats for another girl, to be unattainable as a distant star. Her fate puts and end to a love wasn't hers in the first place, leaving behind her ten letters for her surroundings to bite their hands in regret, especially jeon so. Is it possible for jeon so to be key altering her fate?