Akko es una niña de primaria enérgica y alegre que rompe por accidente un espejo, regalo de su madre. La niña no quiere deshacerse de algo tan importante, por lo que decide enterrarlo con mucho pesar en el patio de su casa. La Reina del Reino de los Espejos, conmovida por tal acto de respeto, decide entregarle a Akko un espejo mágico, con el que podrá convertirse en cualquier cosa que desee. Sin embargo, nadie debe jamás saber sobre el poder del espejo y este no debe ser usado con malas intenciones o por pura diversión o de lo contrario el espejo perderá sus poderes y Akko podría recibir un terrible castigo.

Atsuko Kagami is an elementary school girl who has an affinity for mirrors. One day, her favorite mirror which was given to Akko by her mother (or in some versions, by her father, as a present from India) is broken, and she prefers to bury it in her yard rather than throw it to the trash can. In her dreams, she is contacted by a spirit (or in some cases the Queen of the Mirror Kingdom) who is touched that the girl would treat the mirror so respectfully and not simply throw it away. Akko-chan is then given the gift of a magical mirror and taught enchantments, such as "Tekumaku mayakon, tekumaku mayakon" and "Lamipasu lamipasu lu lu lu lu lu", that will allow her to transform into anything she wishes.