I No Longer Deserve to Be a King!

After the brave man defeated the Demon King, he established a country on the border where humans and demons coexisted. A hundred years later, the throne has been passed to his great-grandson Lu Ze. Faced with population loss and high debts and the approaching demon king, what is his choice? "Sell the kingdom and run away?" "Collect a harem of a hundred people who like you very much, right?" "The King of Kings! I, Lu Ze, am determined!?" All of the above may happen. But before that, let's make some money by becoming a demon hunter or something.