Ultra Maniac Series by Wataru Yoshizumi

Shy Ayu Tateishi has just made a new friend at school. But this new friend, much to her surprise, is no ordinary classmate. Nina Sakura may look like a normal middle school girl, but she's got a big secret. She's a witch. Or, rather, she's studying to be a witch. And, apparently, she's not doing her homework. Her spells are devastating in their ineffectiveness and often result in the most embarrassing situations for poor Ayu... moreShy Ayu Tateishi has just made a new friend at school. But this new friend, much to her surprise, is no ordinary classmate. Nina Sakura may look like a normal middle school girl, but she's got a big secret. She's a witch. Or, rather, she's studying to be a witch. And, apparently, she's not doing her homework. Her spells are devastating in their ineffectiveness and often result in the most embarrassing situations for poor Ayu. But things wouldn't be so bad if Nina's sorcery didn't make Ayu look silly in front of the one boy she secretly adores. All she wants is a simple love potion. What she gets, however, is a new best friend who almost flunked out of witch school! less

When Yuta, a boy from Nina's home-dimension, enrols in her earth school, his motivations are suspect even before he secretly gives her best friend Ayu a camera guaranteed to reveal true love. Ayu quickly learns that love is an emotion most fickle, and not even Nina's magic can predict the target of Cupid's pointed arrow!

Unfortunately, Nina is finding out that going to school on Earth is a lot more complicated than she first thought. Not everybody is glad to have a spunky (and cute) witch flitting about campus. A girl named Sayaka, for example, has recently become obsessed with Nina. A half-witch herself, Sayaka is jealous that her new classmate is stealing all the attention away from her. Like they say in the Magic Kingdom, "There's no fury like that of a teenage witch ignored! ".