Kaede is a cheerful, energetic eighth grader who, despite her vibrant personality, becomes hopelessly shy around boys. One afternoon, on her way home from school, she stumbles into a mysterious shop and purchases a colorful cocoa mug. At home, she casually peers into the bottom of the mug and finds an engraved note: if you read the message aloud while pouring hot cocoa into the mug, a love fairy, known as a muglox, will appear and grant your every wish. Skeptical yet intrigued, Kaede follows the instructions and declares her wish to date Yuuki, the class heartthrob. Suddenly, a cute blue Mirumo, her own muglox, materializes. However, the mischievous little creature is more interested in eating chocolate and causing chaos than helping Kaede achieve her romantic desires.