Blonde and thin, Buffy is your quintessential California girl. Who can kick your ass.
Buffy was born to Hank and Joyce Summers on January 19, 1981, and spends her childhood in Los Angeles, California. As a child, Buffy was close friends with her cousin Celia, and enjoyed playing superhero with her; Buffy pretended to be Power Girl, a prophetic choice of alter ego. She looked on helplessly as Celia was murdered by a demon that preyed on sick children and was visible only to those who were ill, an experience which instilled a fear of hospitals in Buffy. She also took figure skating lessons, idolized Olympic ice skater Dorothy Hamill and attended ice shows with her father. Before moving to Sunnydale, she was a popular student at Hemery High School in Los Angeles where she was a cheerleader and was elected Prom Princess and Fiesta Queen.
The details of how Buffy learned she was the Slayer were first presented in the 1992 movie. However, as this movie is not considered canon in the Buffyverse, Christopher Golden adapted Joss Whedon's original script into a canonical comic book entitled The Origin. In the comic, a fifteen-year-old Buffy is having violent dreams about women from different periods of history slaying monsters. One day, she is approached by Merrick Jamison-Smythe, a mysterious man who reveals her destiny as the Chosen One and becomes her first Watcher (this scene can also be seen in the Season Two episode "Becoming, Part One"). With little training, and help from her friend Oliver Pike, Buffy defeats her first major enemy, a vampire leader named Lothos, but not before the death of Merrick. In a battle with Lothos' vampiric lackeys, Buffy sets fire to the high school gym and is subsequently expelled.
In the Season Six episode "Normal Again", it is revealed that, shortly after her expulsion, Buffy confided in her parents about what really had happened and her destiny as the Slayer. Worried that she was losing her mind, Buffy's parents sent her to a mental institution. While there, Buffy realized that attempts to persuade others of the existence of demonic forces would be futile. She kept quiet and was released after a couple of weeks. Buffy and her parents never spoke of it again. Soon afterward Joyce and Hank, who had been experiencing marital troubles for years, divorced, and Buffy moved with her mother to 1630 Revello Drive in Sunnydale, a small town in California.
In Season One of the series, Buffy begins to accept the responsibilities and dangers of her calling as Slayer. Hoping to be a regular student, Buffy enrolls in the local high school ("Welcome to the Hellmouth") and meets her future best friends, Xander Harris and Willow Rosenberg, as well as her new Watcher, Rupert Giles, together forming the "core four" of the Scooby Gang. She also meets Cordelia Chase, a snobbish cheerleader, and Angel, a vampire with a soul. Buffy is quickly forced back into the role of Slayer as she and her new friends battle vampires, monsters, and demons. She grows closer to Giles, who eventually becomes her father figure. The first season centers on Buffy's battle with a thousand-year-old vampire leader known as The Master and his followers from the Order of Aurelius. On learning that the infallible Pergamum Codex prophesies her death at the hands of The Master, Buffy contemplates leaving town, but accepts her fate after Willow discovers bodies of her friends slaughtered inside the school. She is overpowered by The Master, who feeds from her and leaves her to drown in a pool of water. Xander is able to resuscitate her and she then defeats The Master ("Prophecy Girl"). Her death, though brief, activates a new Slayer, Kendra. (After Kendra's death at the hands of Drusilla at the end of Season Two, the Slayer powers pass to Faith.)
Buffy and Angel
In the show's second season, Buffy continues to come to terms with her destiny as the Slayer with the help of her friends. Buffy finds forbidden love with Angel and clashes with Spike and Drusilla, the new vampires in town ("School Hard"). In the episode "Surprise", Buffy loses her virginity to Angel, unknowingly lifting the curse – his human soul – placed on him a century earlier by a Kalderash clan. Without his soul, Angel reverts to his evil persona. He becomes obsessed with destroying Buffy's life, his pathological abuse taking heavy toll on Buffy and her friends ("Passion"). As Angelus plans to destroy the world, Buffy is forced to reveal her identity as the Slayer to her mother, who demands that Buffy stay home and discuss matters with her, telling her not to come back if she leaves now. As Buffy fights with Angelus, trying to prevent him from opening a vortex to a hell dimension, Willow works a spell to re-ensoul him. The spell is successful, but it is too late, and Buffy reluctantly stabs Angel with a sword, sending him to a hell dimension. Traumatized by these events, Buffy leaves Sunnydale. ("Becoming, Part Two".)
In Season Three, Buffy must reconnect to her calling, her friends, and her family after her abrupt departure at the end of Season Two. Returning to Sunnydale after several months in Los Angeles, she begins to repair relationships with those closest to her as she tries to come to terms with Angel's death and her role in it. However, Angel returns mysteriously and Buffy is still drawn to him. Meanwhile, she must also try to help rebellious new Slayer Faith, who becomes increasingly destructive and disloyal as she indulges her dark side ("Bad Girls"). The writers stated that they created Faith as a way of exploring Buffy's dark side without ruining her character; Faith shows what Buffy could have been without friends or family. Alienated from "the Scoobies", Faith finds a friend in the avuncular yet sinister Mayor of Sunnydale, who is preparing to become a pure-blood demon on Sunnydale High's Graduation Day. When Buffy learns that Angel, who is on the verge of death after being poisoned by Faith, must drink the blood of a Slayer in order to survive, Buffy attempts to sacrifice Faith to save him. Their battle leaves Faith in a coma, and Buffy ultimately saves Angel with her own blood. Thanks to Slayers' rapid healing, Buffy recovers from the loss of blood in time to lead her classmates in a climactic battle against the transformed Mayor and his minions, culminating in an explosion that destroys the Mayor as well as Sunnydale High. As the smoke clears, Angel leaves for Los Angeles so that Buffy can try to have a more normal life without him. ("Graduation Day, Part Two".)
In Season Four, Buffy must balance her Slayer duties with her new life as a college student at UC Sunnydale. Her adjustment to college life is complicated by mystical threats (including, among other things, a demonic roommate, campus werewolves, enchanted beer), the return of Spike (now unable to harm humans), and a disastrous one-night stand with Parker Abrams, a campus player. Buffy also experiences some disconnection from her friends, who all seem to be moving in different directions. She attracts the sincere attention of Riley Finn, who is (as she soon discovers) a member of the Initiative, a U.S. government task force created to research mystical and demonic creatures, led by Buffy's psychology professor, Maggie Walsh. Buffy briefly joins forces with Riley's team. However, Riley and Buffy become disillusioned with the Initiative after Professor Walsh betrays Buffy, and they discover that she is the creator of the cyber-demonoid Adam, the prototype of a race of super-warriors, from the fruits of the Initiative's demon research. Buffy, Willow, Xander, and Giles literally unite to defeat Adam in the penultimate episode of season four "Primeval", by invoking the power of the First Slayer.
Buffy and Dawn
In Season Five, Buffy faces her greatest dangers yet, while finally fully embracing her destiny. A younger sister, Dawn, mysteriously appears in Buffy's household, her existence having been seamlessly integrated into the memories of Buffy, her mother and her friends. Buffy discovers that Dawn is not her sister and soon learns that a group of monks "created" a human body in order to hide "The Key," cosmic energy that can open inter-dimensional portals, from a mentally unstable and dangerous hell-god known as Glory. Meanwhile Spike slowly becomes aware that he has fallen in love with Buffy, and he becomes a more regular and reliable presence in her Slayer life, assisting in the fight against demons. Buffy suffers much emotional turmoil throughout this season, such as the deterioration of her relationship with Riley and her mother's unexpected death from a brain aneurysm ("The Body"). While on a vision quest, the spirit of the original Slayer tells her that "death is her gift," a message she has difficulty understanding. In the season finale "The Gift", Buffy finally understands the meaning of the message and sacrifices her own life for Dawn's. She dives into an inter-dimensional portal, closing it and saving the world. She is buried in the wooded outskirts of Sunnydale with the epitaph, "She saved the world. A lot." Finally able to rest, Buffy ascends to heaven and finds peace.
Except in this time frame, Buffy ended up in the Sueniverse.