Jane Espenson and Drew Greenberg will debut Billy - who does not possess slayer superpowers - in issue #14 of the canonical Dark Horse Comics series.
Espenson devised the character while working on her web series Husbands.
"I already knew [the character] Cheeks, and he has a line in Season 1 of Husbands, that Brad [Bell] wrote, that really struck me about how Cheeks has an 'exotic femininity' that's equated with weakness," she told OUT.
"I thought: 'Gee, all the work we've done with Buffy is about being female, and how that doesn't mean that you are lesser'. It suddenly struck me: If being feminine doesn't mean that you're lesser, then liking guys also doesn't mean you're lesser.
"For very good reason, we've focused on the female empowerment part of Buffy, but I wondered, 'Did we leave something out? What if someone in high school is looking up to Buffy as a role model, and we're saying: You can't be a slayer'."
Billy is a character who trains himself to fight like a vampire slayer.
"He may not have the actual powers of the slayers, but he's determined to be his own kind of hero, one who's sort of modelled after those who do have the power, and he sets out to make due with what he has," said Greenberg.
Espenson promised an "honest" story.
"We're hardly pandering when we make a comic book," she said. "There's always growing pains when making progress, but I think cynicism in the face of inclusion may not be a profitable route in making progress."
Espenson and Greenberg's two-part story will launch in Buffy the Vampire Slayer Season Nine #14 on October 10