A popular 16+ Rated manga by Ken Akamatsu, Author of Love Hina, AI Love you, and many more. Main character is Negi Springfield, a british mage come to teach english at a Japanese females only school. Negi always ends up getting himself into some pervertted situation not suitible for 10 year olds.
Ex. What volume of Negima are you up to?
Well I'm so cool I read it online, way past what has been released in America