Luna-"And I don't know who you are.
Luna Lovegood first met Neville Longbottom in her fourth year when Ginny Weasley suggested to he and Harry Potter that they sit with her in a compartment. At first, Neville didn't seem too keen to get to know her, but Luna treated him well and they became friends. They were also leaders of Dumbledore's Army with Ginny Weasley when Harry left.
There have been many videos on YouTube and plenty of fanfictions about people expressing their wish for Neville and Luna to be together. They say that they wish that J.K. Rowling had never even made up Hannah Abbott and Rolf Scamander. They also say that both Neville and Luna were somewhat "outcasts", and they should have ended up together.