One aspect of the MTT universe that is frequently neglected on websites is the Mahoutsukai tai! manga. It's relatively obscure and hard to find, so this is understandable ^_^; As far as I know of there are two series. One is a shonen (male-targetted) version published by Kadokawa Comics by "ShamNeko". This version is more recent, and stays truer to the OAV character designs. Not much more to say, I wasn't as fond of it as the other.
The one I'm more familiar with is a manga series done by Tammy Ohta, which was released either at the same time or a little later than the OAV (I'm sketchy on the timeline, but a comment of hers in a Q & A at the end of volume 2 leads me to believe the OAVs already existed ^^;). While the OAV series has more of a shonen touch to it, this manga is designed to be most definitely shoujo ^_^;
So far I've been able to find 4 volumes. The series ran in Asuka Fantasy DX. It's a lot different than the OAV. The character designs vary (especially Sae, Takeo, and Mizuha O_o) as well as the plot. The story begins before the OAVs start, with Sae and Nanaka's freshmen year (and them joining the magic club). It introduces a magic club member not in the OAVs (Peter), and continues onto the next year, introducing Akane and the Tsurinage. The plot differs dramatically with more magic and romance focused hijinks and less action with the Tsurinage. Jeff is also a more prominent character/plot device. Some characters are paid much less attention, such as Mizuha; the camera-man and reporter don't even exist ^^;
Just because it's different doesn't make it bad; I like it, I think it's cute, but in a more shoujo-romantic angst drama type way ;) If you'd like to aquire them for yourself, there are ISBN numbers below. (Images of the covers acquired from "where all the little bears come to play", which seems to have gone offline)