The premise of "Buffy the Vampire Slayer" is that Buffy Summers, a high school student played by Sarah Michelle Gellar, must balance her life as a teenager with her life as a vampire slayer. Buffy is aided by her friends and family in her fight against evil.
"Buffy the Vampire Slayer" is set in the fictional town of Sunnydale, California, where Buffy Summers is a student at Sunnydale High. As a woman chosen by fate to be "the slayer," Buffy receives assistance in fighting evil from her Watcher, Rupert Giles, played by Anthony Stewart Head. She also receives help from her friends, such as Willow Rosenberg, who is a witch played by Alyson Hannigan, and Xander Harris played by Nicholas Brendon.
New characters are introduced throughout the course of the series, changing the dynamic of the show. In the first season, Buffy encounters a vampire named Angel, who becomes her love interest through the first three seasons. Angel breaks up with Buffy, believing he isn't good enough for her, and goes on to appear in the spin-off series "Angel."
Spike, a vampire played by James Marsters, begins as one of Buffy's enemies, only for them to become friends and lovers. In the fifth season, Buffy's sister, Dawn Summers, played by Michelle Trachtenberg, is introduced.