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 ‘Sir Royce’ 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?