I'm The Only Granddaughter Of The Strongest Duke

Lord, please allow me to sabotage his business again today. That’s how my dad will not die. A weaponsmith who lost his life while crafting weapons for the warrior’s party. That foolish man was my father. Upon realizing the future, I took drastic measures in order to save my dad’s life. That was through sabotaging his business! “Darn it, why is such a cool sword can’t even cut this tiny potato-!” “It can’t even slice the ham this time!” “There’s no way that the sword made by ‘ would be this useless-!” My trick to sabotage his business was successful. But I didn’t stop here. I spoke courteously to the warriors who came for my father. “Nial Royce? I don’t know that person. I only live with my mom.” Sorry, father. My plan was a huge success. Only flies flew to my father’s weapon store, and the warriors didn’t come to ask for a sword from my father. I thought I could live happily with my father now… “You….How old are you this year, child?” The most powerful duke of the empire suddenly claimed that I was his granddaughter. What the hell is going on here? What is happening with me?