Well, in this one they were once friends who have to make their way back to each other:
Anything But Ordinary by Sweetiehttp://www.sinister-attraction.net/stories/s/anythingbut.htmSummary: Fantasy fic. In the words of Buffy Summers, "We were friends until I was fourteen. Then high school came along, he became gorgeous, and I became a pronounced loser." Yep, this is a high school fic, guys... with a twist. Can enemies, Buffy and Spike, rebuild the friendship they used to know? Will it develop into more? There are other 'used to be together but fell apart and now work their way back to each other' fics out there but most of the ones I know are post-high school. Some they were together in high school and then get back together later, and others they were adults when they were together. How important is the high school only part to your request?