The premise: Buffy (Sarah Michelle Gellar), an ordinary teenager at Sunnydale High, discovers that she is The Slayer, one girl out of all the world given the super powers necessary to kill vampires and other demonic beings. She and her allies make wisecracks and discuss trivial home-and-school issues as they fight the monster of the week.
Every season has a story arc with an Apocalyptic threat by the "the worst enemy we have ever encountered" (by the later seasons, the hyperbole becomes tedious). Also lots of romantic entanglements.
1.-3. "Regular guy" Xander (Nicholas Brendon, top photo), who dates snobbish Cordelia, and then Anya, a 1000-year old vengeance demon
4.-6. Computer whiz/witch Willow, who dates the sardonic werewolf Oz (Seth Green), and then the mousy Wiccan Tara.
7.-8. Watchers (professional Slayer mentors) Giles and Wesley
9-11. Buffy's boyfriends, reformed vampires Angel and Spike and military vampire-hunter Riley (Marc Blucas, below)
12, Her sister Dawn.
Male bonding: Not much. The primarily relationships are always male-female or female-female. The male Scoobies treat each other as cordial coworkers.
Gay characters: Two minor gay male:
1. Larry, a football star, originally accused of being a werewolf in Season 2. Xander discovers his "real" secret, and freaks out. He reappears several times, out and proud, during Season 3.
He appears in the spinoff Angel with a blatant crush on reformed vampire Spike (James Marsters, left). But later, he appears surrounded by beautiful women and comments: "People change." Creator Joss Whedon explains that Andrew wasn't supposed to say the line -- it was to go to a female character, who was supposed to be surrounded by beautiful people.
In Season 7, Willow gets a new girlfriend, streetwise Slayer-in-training Kennedy.
See also: Hansel and Gretel: Witch Hunters; and MyMusic, a webseries starring Adam Busch (who played a villainous nerd).