Mirmo!

The main protagonist, a love fairy named Mirmo (Mirumo) appears. Katie Minami (Kaede Minami in the original Japanese versions), is a cheerful and energetic eighth grader who is shy around her male classmates, making it difficult for her to date. One day, on her way home from school, she walks into a mysterious shop and buys a blue cocoa mug. When she arrives at home, she peeks into the bottom of the mug and discovers an engraved note which says, "If you read this message aloud while pouring hot cocoa into the mug, a love fairy ("muglox") will appear and grant your every wish." The skeptical but curious Katie follows the directions and announces her wish to date Dylan Yuki (Setsu Yuuki in the Japanese versions), her crush. Arrive Mirmo. At first she was afraid of him but later understood that he was a muglox. Katie soon finds out that Mirmo prefers eating chocolate and creating mischief over helping Katie.

It turns out Mirmo is prince of the muglox world. Horrified at the prospect of having to marry Rima (Rirumu), his princess bride-to-be, Mirmo escaped the muglox world. Hot on his heels, however, are Rima, Yatch (Yashichi) the bounty hunter, Murumo (Mirmo's brother), and many other muglox as well.

The main characters of Mirmo! are four human teenagers and their mugloxes, or love fairies. The muglox Mirmo has been assigned the task of granting Katie Minami's wishes, though he spends most of his time eating chocolate and running away from Rima, a female muglox assigned to Dylan Yuki, the boy Katie is infatuated with. Yatch, Mirmo's muglox archrival, is assigned to by Azumi Hidaka, a girl who also loves Dylan and is jealous of Katie. Mirmo's brother, Murumo, is assigned to Kyle Matsutake, a boy who falls in love with Katie. The muglox fairies use musical instruments as their magical tools. Later on in the show two new characters, Koichi Sumita and Haruka Morishita, enter the race of love for Dylan and Katie's hearts. Then they get their very own muglox partners as well - Papii and Panta, respectively.