A troubled kitten in His Highness's arms

"I love you, Nelly." With those words, open arms reach out to embrace them. A childish promise made in exchange for wanting to stay in those arms forever. After ten years had passed and she had completely forgotten, that promise appeared before Malneletta. The one who made the promise was the Prince, and he tells Malneletta that from now on she will live in the royal palace. A granddaughter of a small feudal lord from a remote rural area, struggling while bewildered by the difference in social status—this is supposed to be a historical-style love romance set in a European-style alternate world.