KAICHOU WA MAID-SAMA!

Also known as "Our student Council President is a Maid!" Kaichou wa Maid-sama! is a shoujo manga series by Hiro Fujiwara. It Genres are Comedy, Romance, School Life and shoujo (main character is a girl).
It is one of the top anime and manga.
 The story goes like this:
                                   

Once an all boys school, Seika High School, a renowned school full of reckless and filthy students, has recently become a co-ed school. However, with the female population still remaining a minority even after the change over the recent years, Ayuzawa Misaki takes it into her own hands to reform the school and allow a chance for the girls to feel safer in the rough environment.

Training, studying and even becoming the first female student council president of the school, Misaki has gained a reputation, among the male students body as an uptight boy-hating demon dictator and as a shining hope for the teachers and fellow female students. However, despite her tough-as-nails appearance, she secretly works part-time at a maid cafe in order to support her family. Unfortunately, her secret is soon revealed when the somewhat impassive Usui Takumi, a popular boy at school, nonchalantly discovers her in a maid uniform after school.

          

Usui is one of the most popular boys at school. He's in fact an illegitimate child; his rich English mother (whose maiden name is Usui) had an affair with an unknown Japanese man. He proves to be extraordinarily talented in a number of different fields, including cooking, the violin, chess, and table etiquette.
 He regularly tells Misaki he likes her, but she dismisses his behavior simply as a joke or harassment. Usui truly cares and loves Misaki but he is waiting for the right time for them to be together and officially date each other.
One of the reasons of Usui's attraction to Misaki is that she is  always driven to do her best regardless of the endeavor, and has a strong sense of justice, though she also has a tendency to forget her own well being in the process of helping others. Misaki harbours feelings towards Usui and often blushes when he's around her but she always denies it and says that she hates Usui, but it usually means she loves him.