Doremi Harukaze, a third grade elementary school girl living in the fictional Japanese town of Misora, comes across an esoteric shop known as the Maho-Do (MAHO堂), accidentally discovering that its owner, Majo Rika, is a witch. Due to a curse placed on any witch whose identity is exposed by a human, Majo Rika is transformed into a magical frog. Wanting to return to her original form, Majo Rika makes Doremi her witch apprentice, giving her the ability to cast magic. Feeling guilty for placing that curse on her, Doremi accepts Majo Rika's offer in hopes of fixing her mistake. In order to become a fully-fledged witch capable of turning Majo Rika back into a human, Doremi has to pass nine different witch tests, whilst also keeping her identity a secret from other humans. Doremi is soon joined by her two best friends, Hazuki Fujiwara and Aiko Seno, and later by her younger sister Pop Harukaze who all become witch apprentices, helping to run the Maho-Do whilst using magic to help out their friends and families, with the occasional mishap. They soon come across a rival witch apprentice, Onpu Segawa, who has been using forbidden magic to influence people's memories. Whilst initially cold towards the other girls, Onpu soon warms up to them and sacrifices herself by wiping the memories of those that attempted to expose them (wiping memories is a witch taboo) to prevent their identities from being revealed. In order to save Onpu from an eternal sleep, the girls give up their magical powers to awaken her.