Who is the hero?

Celestia, the youngest daughter of the late emperor, was born in his later years, and was raised more like a younger sister to her nieces and nephews than to her actual older siblings. Her swordsmanship, which she began learning alongside the crown princes in her early childhood, improved by leaps and bounds. Eventually, under her older brother, she became a Black Knight and took on the role of gathering intelligence on neighboring countries... *A comedic daily life and romance of a hard-working girl.