Which J.K. Rowling book does Emma Watson's character first appear in?
Harry Potter and the Chamber of Secrets (film):  The film stars Daniel Radcliffe as Harry Potter, with Rupert Grint as Ron Weasley, and Emma Watson as Hermione Granger. Hermione Granger: Hermione Jean Granger ( ) is a fictional character in J. K. Rowling's "Harry Potter" series. Hermione Granger:  She first appears in "Harry Potter and the Philosopher's Stone", as a new student on her way to Hogwarts.
"Harry Potter and the Philosopher's Stone"