If you liked the Rosario to Vampire anime, the Anime-Planet community thinks you'd like:
Maya Kumashiro is an uptight teenager who has returned to the Waldstein “Occult Academy” following her father’s death to assume his role as principal. With a hatred of the supernatural, she initially intends to run the school into the ground, but her plans are thrown into chaos when a new teacher, Minoru Abe, descends from the sky. Claiming to be a time agent, Abe informs Maya that he has been sent from the future to prevent the Nostradamus prophecies from coming to pass. With a rift to another dimension due to open at the Waldstein Academy that will lead to aliens conquering the earth, the unlikely pair must locate a mysterious object known as the Nostradamus Key and destroy it before humanity falls prey to the occult once and for all.
Both Rosario to Vampire and Occult Academy have similar themes. Secret academies that cater to students interested in the occult. Although varying greatly in execution and content, they are both worth watching if the magical school anime is your thing.
While visiting his hometown, junior high school student Michishio Nagasumi's life was changed forever when he nearly drowned. Though he was saved by a mermaid named San, there’s a catch -- her family is part of a merfolk mafia, and they abide by a strict rule: If a mermaid is discovered by a man, either he or the mermaid must die. That is, unless the man marries into the family! Faced with such a decision, Nagasumi can only oblige their customs and become a "happy" newlywed. Now, with a new school year around the corner, Nagasumi must find a way to deal with his new bride, keep her true nature a secret, and most importantly, escape inevitable death at the hands of San's over-protective father’s gang!
Both of these anime involve a boy that gradually finds himself surrounded by supernatural women. The main girl is rather ditzy until she has to defend the people she cares for. With others vying for the guy's attention, school life, and trying to keep the girls' powers a secret, these anime are pretty similar.
Sakai Yuuji thought he was a normal high school student, until one fateful day when time stopped. Watching in horror, he witnesses a monster devouring the "frozen" people around him; but luckily for Yuuji, he is saved by a sword-wielding red-headed girl that calls herself a "Flame Haze". The girl informs him that he has been dead for some time now and that his current self is merely a replacement for the human that he used be while alive. He is, she says, merely a torch whose life will come to an end when the blue flame in his chest ceases to burn. After this rude awakening, Yuuji realizes that he is able to see the flames of life in other "torches"; and after discovering that a friend of his is also a torch -- and her life is burning out faster than his – he gains the courage to live out the rest of his life with meaning. Will Yuuji be able to find his place in the world before he ceases to exist?
Both series tell a story of a pathetic boy wo is protected by a girl through his life. Additionaly they fight demons. If you like that kind of stu there is a high propability that you will like the show I find similar.
Ever since Tomoki was a boy, he’s dreamed that the girl he loves vanishes into the sky. However, while he’s convinced it’s just a dream, his classmate Sugata is convinced that it’s related to an alleged ‘new continent’ that’s floating around the planet. According to Sugata’s calculations it’s set to pass above their town at midnight, and sends Tomoki to check it out. Little did Tomoki know that at that moment, a scantily-clad angel would fall from the sky! Calling herself a pet-class Angeloid named Ikaros, she promises to fulfill Tomoki’s every wish. Now, Tomoki is able to manipulate panties and do equally as perverted things with ease; but what is Ikaros really here for, and are her motives as pure as they seem?
In a bizarre fantasy world, students known as meisters are trained at the illustrious Shinigami Weapon Meister University; but the tools they wield are no ordinary weapons! Each meister is paired with a human-like being who can transform into a weapon at will; and after defeating a pre-kishin - a human whose soul has darkened - the weapon eats the soul within it. A meister's ultimate goal is to collect ninety-nine pre-kishin souls and one of a witch so that his or her partner will become an all-powerful Death Scythe. Maka and her partner Soul Eater; Assassin Black Star and his partner Demon Blade Tsubaki; and Shinigami's son Death the Kid and his partners the Demon Twin Pistol Thompson Sisters each vie for their ultimate goal, but plenty of challenges and adventures lie in their way!
If you loved Rosario to Vampire's school for famous monsters concept, then be prepared to have your mind blown by Soul Eater. An exponentially better series, Soul Eater takes classic monsters, and puts a fresh anime twist to them, packed full of comedy and action.