Ultra Maniac

Plot
Ayu Tateishi is a well-adjusted middle-schooler in her second year, until the fateful day when she finds a dejected looking Nina Sakura outside of the school. Nina explains that she lost something very dear to her earlier that day. Ayu offers to help Nina look for her lost item, but Nina seems reluctant to say what the item is that she lost, and runs off. On her way home Ayu finds what seems to be a mini-computer underneath the bench she knew Nina to be at earlier that day. After returning the item to Nina, Nina struggles to decide whether to let Ayu in on the 'big secret' she keeps.

In order to see if Ayu is trustworthy, she starts to follow Ayu around and eventually decides she can trust Ayu. Nina reveals that she is actually from the Magic Kingdom and is a magic girl. Ayu, however, doesn't believe Nina and thinks she is a bit crazy at first. Ayu herself had always shunned the ideas of magic and fairy tales, even admitting she had never read Harry Potter, so having someone tell her they are a witch truly isn't something she can easily accept. After several mishaps with her magic, Nina proves she is a magic girl, and a failure who came to Earth as her last chance to prove that she can get things right. These first mishaps and the fact that Nina has shared her secret with Ayu, Nina attaches herself to Ayu as a friend and does everything she can to help Ayu with getting the attention of the boy she loves. As their adventures continue many friends from the magical kingdom come and visit Nina to the chagrin of Ayu.

The anime adaptation has a very different plot starting after Ayu and Nina have first met. Instead of coming as a witch failure who is trying to prove herself to be more than she is said to be, Nina has come to Earth to find the five "Holy Stones". She tells Ayu that whoever collects all five will qualify to marry the prince of the Magic Kingdom. Nina's childhood friend Maya is also on Earth from the start, competing with Nina to find the stones. Though Nina does collect them all first, she learns that the prince and Maya are truly in love with one another, so Nina gives up the stones and her dream, allowing Maya and the prince to be with one another, and Nina stays on Earth with her friends.