Demigods Go To Goode
Percy goes back to Goode High School and faces his old friends questions of why he disappears last year.
Piper gives high school another shot. Her dad chooses the school, Goode, but Piper is fine with it because she knows she has a friend there. There she faces guys who thinks she's hot, and mean girls.
Together the two become closer than before, in a brotherly and sisterly way, of course. Dealing with school drama.
Other demigods may appear. I don't know you'll have to check it out.