Haru Yoshioka is somewhat awkward for a high school student, often screwing up in public and, to her dismay, in front of her crush Machida. One day, Haru saves a cat from being hit by a truck—only to see the cat stand up and thank her for her kindness before running off. As if that wasn't weird enough, a large group of cats arrive in front of her house later that night with the cat's father, a Cat King, thanking her for saving his son, Prince Lune.

To further show his gratitude, the Cat King gives Haru a tablet that describes that she will receive five gifts: lacrosse sticks to make up the one that broke while saving the prince, a field of green foxtails, catnip, canned mice—and marriage! Haru expresses her displeasure for the gifts to one of the king's servants, but the servant unfortunately takes her answer toward the marriage offer to Prince Lune as a "yes." Unsure of what to do, Haru is directed by a voice who tells her to go to the Cat Office for help—but will they be able to help her with this problem?