Yui, an expert housekeeper, is not a big fan of cats. While she is busy supporting her family, she takes on housework for a man named Yoru Shinonome. He is a painter and illustrator, and with his jet-black hair and beautiful eyes, he is a "black cat" himself! Yui finds his words and actions to be cat-like and finds him difficult to deal with, but he recognizes her work ethic and for some reason, she is drawn to him...?