I'll introduce the franchise for you:
The Negima! manga is written by ken Akamatsu, it starts off like some Love Hina-ripoff, with a ten-year old boy being surrounded by school girls.
Then stuff happens, and he uses magic and fights and some of the girls fight as well. And the manga becomes epic.
Now, the first anime only focused on the harem part, the second focused on some fighting, but had a completely different storyline.
This one, like, the fourth or something, takes place around the middle of the manga, when they enter the magic realm to find clues about the main character's father.
What I'd really recommend is reading the whole manga. But do as you want.