rosario + vampire

Tsukune Aono is a normal high school freshman who is unable to get into any private school due to his poor grades. However, with help from his parents, he gets enrolled to a private school called Yokai Academy. When he arrives at the school, he soon discovers that Yokai Academy is a secret school for supernatural monsters and mythological creatures disguised as humans, and any human who finds out about its existence will be killed without mercy. Realizing this, Tsukune fears for his life, thinking that his admission into Yokai Academy is a mistake. His luck soon changes when he quickly becomes friends with the beautiful Moka Akashiya, who turns out to be a vampire attracted to the sweet taste of his blood, sometimes biting Tsukune on the neck when the chance seems right. While at first Moka was upset upon discovering Tsukune's human identity, she realizes that he is the first real friend she had ever made. Despite Moka's vampiric nature, she is a kind girl and Tsukune quickly falls for her, and ultimately decides to stay at Yokai Academy despite the various dangers while hiding his human identity from the faculty and other students. Tsukune soon discovers that when he removes the rosario around Moka's neck, she transforms into her true vampire form (her true personality is sealed, the kind Moka being an artificial persona), being stronger and more powerful than almost any other creature at the school, and Tsukune is the only person who can physically remove it to transform her. However, "Inner Moka" has an entirely different personality, often cold and merciless, thus the rosary is only removed in dire emergencies.

As the school year continues, Tsukune becomes involved with other students who start out as enemies but who are won over into becoming his friends: Kurumu Kurono, a busty succubus; Ginei Morioka, a perverted lech of a werewolf who is a second-year student and president of the school's Newspaper Club; Yukari Sendo, an eleven-year-old witch; Ruby Tojo, a witch from the human world, and Mizore Shirayuki, a yuki-onna (a teen version of the legendary snow woman of Japanese folk tales) who stalks around Tsukune, believing them to be soulmates. However, after Tsukune befriends each of the girls, they become friendly rivals along with Moka, vying for Tsukune's affections, and later most become members of the school's Newspaper Club with Tsukune and stand by him even after they learn that he is really a human.

Later on in the second manga serialization, Kokoa Shuzen, Moka's younger half-sister, appears, and as time goes on, they discover dangerous organizations like the Anti-Schoolers and Fairy Tale, and must do battle against them to keep the school and both the monster and human worlds safe, and Tsukune starts to undergo changes that will truly solidify his role as the link between the human and monster worlds.

Yokai Academy

Yokai Academy (陽海学園, Yōkai Gakuen^?) is a special school made for the purpose of monsters coexisting with humans. It is founded by the three Dark Lords, one of whom is the dean of the school. Yokai Academy is surrounded by a barrier called the Great Barrier (大結界, Dai Kekkai^?), which separates the academy from the human realm, hiding it from plain sight. The only known way to get to Yokai Academy from the human world is through a bus that travels through a tunnel called the "Tunnel of the Fourth Dimension", which, according to the bus driver, has various "mouths" that open to various tunnels all throughout Japan. The barrier is powered by a rosario seal that is similar to Moka's deep within the academy, and according to Mikogami, if the barrier collapses, all of the suppressed energy contained in the yōkai world will flood over to the human world, creating chaos and disorder.