Hermione Jean Granger (icon) is a fictional character and one of the three protagonist

Protagonist

A protagonist is the main character of a literary, theatrical, cinematic, or musical narrative, around whom the events of the narrative's plot revolve and with whom the audience is intended to most identify...

s (the other two being Harry Potter

Harry Potter (character)

Harry James Potter is the title character and main protagonist of J. K. Rowling's Harry Potter series. The majority of the books' plot covers seven years in the life of the orphan Potter who, on his eleventh birthday, learns he is a wizard...

 and Ron Weasley

Ron Weasley

Ronald Bilius "Ron" Weasley is a fictional character and one of the three protagonists in the Harry Potter book series written by J. K. Rowling. His first appearance was in the first book of the series, Harry Potter and the Philosopher's Stone as the best friend of Harry Potter and Hermione Granger...

) in J. K. Rowling

J. K. Rowling

Joanne "Jo" Rowling, OBE , better known as J. K. Rowling, is the British author of the Harry Potter fantasy series...

's Harry Potter

Harry Potter

Harry Potter is a series of seven fantasy novels written by the British author J. K. Rowling. The books chronicle the adventures of the adolescent wizard Harry Potter and his best friends Ron Weasley and Hermione Granger, all of whom are students at Hogwarts School of Witchcraft and Wizardry...

series. She initially appears in the first novel, Harry Potter and the Philosopher's Stone

Harry Potter and the Philosopher's Stone

Harry Potter and the Philosopher's Stone is the first novel in the Harry Potter series written by J. K. Rowling and featuring Harry Potter, a young wizard...

, as a new student on her way to Hogwarts

Hogwarts

Hogwarts School of Witchcraft and Wizardry or simply Hogwarts is the primary setting for the first six books of the Harry Potter series by J. K. Rowling, with each book lasting the equivalent of one school year. It is a fictional boarding school of magic for witches and wizards between the ages of...

. After being saved in the girls' bathroom from a mountain troll

Troll

A troll is a supernatural being in Norse mythology and Scandinavian folklore. In origin, the term troll was a generally negative synonym for a jötunn , a being in Norse mythology...

 by Harry and Ron, she becomes close friends with them and often uses her quick wit, deft recall, and encyclopaedic knowledge to help them.