Gio's and Joanne's "Ikaw at Ako" and "You and Me" tattoos were the real handwriting of Reid and Lustre.
Squid Ink, the tattoo shop where Gio works, was built from scratch.
Norman King, the first Aeta graduate from the University of the Philippines, was Lustre's Zambal coach.
The movie's initial concepts and screenplay drafts were inspired by these two quotes: "Ang great love mo, hindi mo makakatuluyan. Ang makakatuluyan mo ay 'yung correct love," from Ricky Lee's book Para kay B; and "We love just once in a lifetime and spend the rest of our lives looking for something similar," an old Russian saying.
The ending song could've been "Landslide" by Stevie Nicks. But seeing how "Prom" had so much impact in Gio and Joanne's love story, Jadaone decided the latter would be the better song to end the film.