If you're looking for anime similar to Rosario to Vampire, you might like these titles. All recommendations are made by Anime-Planet users like you!
Ten-year-old genius Chiyo, animal-loving Sakaki, loudmouth Tomo, athletic Kagura, weight-conscious Yomi and dim-witted Osaka are six friends who share laughs, good times, and a high school homeroom. With scary (and sometimes perverted) teachers, school festivals, penguin suits and general hilarity abounding, you can be sure that there's never a dull day in the life of one of these students!
Why these two when Rosario is clearly more ecchi than Azumanga? Well, because Azumanga parodies the ecchi school girl anime (see Kimura for reference), and because both of these animes are a lot of fun. While Rosario has a bit more fighting and drama, Azumanga is not without its share of hilarious action. School trips, girl geniuses, and mentions of breat-size float between these two animes.
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.
When the students of class 2-A at the all-girls Mahora Academy head back to school, they are expecting a new year as usual. What they get is a new homeroom teacher... who's 10 years old! As if being a genius isn't enough, Negima is a mage. As part of his training to be a Magister Magi, he must succeed at teaching - without anyone finding out he's a magician! Can Negi keep his talents a secret from the girls who just adore the cutest new addition to their academy? Through demon attacks, magical enemies, and English tests, Negi will put all his talents to the test to be the best teacher he can and achieve his goal of Magister Magi.
$10 can not only buy you a cute hamster; it also get you a devoted housekeeper who will cook, clean, put on suntan lotion, and cheer you on when your relationships get stale! Does it seem like a dream? Then picture what life would be like if anybody who calls your house gets to know the contents of your underwear drawer! If you can’t imagine what rodents and ecchi have to do with each other, then enter the life of the hamster Ebichu, her sexy master, and the good-for-nothing boyfriend Kaishounachi, and see why a talking hamster can be such a bother!
Having failed to earn admission to a university, Hideki Motosuwa has moved to the big city, determined to study his hardest for next year's exams. However, an unusual distraction presents itself one unsuspecting day in the form of Chii, a robotic young girl that has been discarded in the trash. In a world where an increasing number of people turn to these 'persocoms' for company, the bonds and limits of human relationships are tested as flesh manages to fall in love with the machine itself...
Both anime's follow a similar style. Chobits is a little more innocent in terms of sexual scenes where as Roasio to Vampire's sexual scenes are literal. Both anime's can be geared towards both males and females, though I believe males might find these two slightly more enjoyable. There's a few cutesy moments in each of them but the majority is literally mindless sexual references backed up by a minimal plot line.My recommendation is that if you don't mind sexy anime's then give these two a shot.