The story follows a girl called Haru, a quiet, shy and unassuming high school student who has a long-suppressed ability to talk to cats. One day, she saves a darkly-coloured, odd-eyed cat from being hit by a truck on a busy road. The cat turns out to be Lune, Prince of the Cat Kingdom. In return, the cats shower her with gifts of catnip and mice. She is then offered the Prince's hand in marriage.