I'll be Taking Over this Duchy

"I was a noble this whole time?!" Hilde, a commoner who works at a restaurant in the village, is suddenly notified by a handsome man named Logan that she is a family member of one of the empire's four duchies and hears that her mother 'Lucia Arpeggio' was a powerful mage in the past. Duke Arpeggio offers to make her an official member of the family if she can prove that she has strong magical powers, and Hilde accepts in order to escape from her oppressed commoner livelihood and enjoy a comfortable life. However, her excitement doesn't last long… Culture, magic, history, literature, etc. The number of things nobles needed to learn were endless! In addition, forget about welcoming Hilde, her family members only sent her cold looks and even put her life in danger… "You've left me with no choice. I, a former commoner, will be taking over this duchy!"