The first season exemplifies the "high school as hell" concept. Buffy Summers has just moved to Sunnydale after burning down her old school's gym and hopes to escape her Slayer duties. Her plans are complicated by Rupert Giles, her new Watcher, who reminds her of the inescapable presence of evil. Sunnydale High is built atop a Hellmouth, a portal to demon dimensions that attracts supernatural phenomena to the area. Buffy meets two schoolmates, Xander Harris and Willow Rosenberg, who help her fight evil through the series. She also gets a love interest in the form of Angel, a vampire who has a soul. They soon become known as the "Scoobies". Together they must prevent The Master, an ancient and especially threatening vampire, from opening the Hellmouth and taking over Sunnydale.
While befriending Buffy on her first day, both Willow and Xander have motives to fight. Xander's motive to fighting alongside Buffy was the loss of his friend Jesse, who was turned into a vampire by The Masters' minions. Xander soon kills Jesse. Willow however was more timid and fiercely scared of monsters. They both soon become Buffy's most loyal sidekicks. There is some romantic tension between them as Xander has a crush on Buffy while he is oblivious of Willows affections for him. The Scoobies distrust Angel but warm up to him as the season progresses.
Buffy and her friends often clash with Cordelia Chase, who attempted to befriend Buffy on her first day, but Buffy didn't like the way she treated Willow. Throughout the season, Cordelia was often at odds with Buffy and her friends but near the end of the season, she becomes aware of the supernatural world around her and helps Buffy.
In the earlier episodes, Buffy and Angel encounter The Master's favorite minion Darla, who was the vampire who sired Angel. Darla is soon killed much to The Master's anger, but The Master gains a new ally in the form of the Anointed One, a child like minion who has a major role in opening the Hellmouth.
In the season finale, Buffy learns of a prophecy involving her death at the hands of The Master. Just as The Master begins his plot, Buffy finally confronts him. The Master bites Buffy and leaves her to drown in a shallow pool. Buffy recovers via CPR by Xander and confronts The Master again on the school roof. After a final stand off, The Master is impaled and killed on a piece of wood after falling through the Sunnydale High skylight. After saving the world, Buffy and her new friends go to a party.