Back to anime, then. And back to anime I'd neither seen nor heard of.
Kanzaki Megu-chan is a 15 year old girl who is a possible successor to the throne of the Magic World. As part of her test, she is required to go to the Human World to learn about how human beings live on Earth. You see, in Meg's world, there are no families – they don't even understand the concept of family…
A 1974 Magic Girl show coming on the heels of Go Nagai's Cutey Honey. It shares an animation director in the shape of Shingo Araki and also theme performances by Yoko Maekawa. It's another show considered by some to be one of the major influences on the genre (even though it's basic plot can be said to come directly from Sally The Witch).
One element it does have that can be seen clearly today is the idea rival Magic Girls. The site I've linked to above goes on to explain that Megu has a rival for the throne, Non who is also sent to Earth.
Hmm… Rival witches sent to Earth to determine who gets the throne… that sounds familiar…
Even Sugar Sugar Rune's theme seems a call back of sorts to Yoko Maekawa's 70's themes