Anna Todd, the author of One Direction-inspired fan fiction "After," recently revealed whom she would cast for the upcoming film adaptation.

According to Deadline, Paramount Pictures now has the screen rights to Todd's Wattpad hit/popular novel, which generated 1 billion reads online. Also, Adam Shankman and Jennifer Gibgot (Offspring Entertainment) have been chosen to produce the movie.

The first-time author explained how she started writing the original three-part series. "I was reading fan fiction on Wattpad, but they were taking a little bit to update the stories, so I started writing my own stories to entertain myself," she revealed to E! News. "I didn't think anyone would read it."

Todd then discussed using all five members from the British boyband in her story: "Liam [Payne] is Harry's [Styles] stepbrother in the book. In the book Harry is Hardin, Louis [Tomlinson] is Logan, Liam is Landan, Niall [Horan] is Nate and Zayn [Malik] is Zedd."

"After" centers on the romance between a college girl named Tessa and the Styles look-alike, who "is in college not in a band." "It's a love-hate thing between Harry and Tessa. They hate each other in the beginning and they fight and then they fall in love," said Todd. "She breaks down all of his walls. It's a very dramatic turn on. They are back and forth and up and down."

"There are definitely sex scenes. I mean, I was writing it for myself... There are adult scenes in the story. There is no S&M," she added. "They are regular sex scenes, but very detailed. It's the vanilla version of 'Fifty Shades of Grey'!"

Lastly, Anna Todd revealed that she would cast Harry Styles in the forthcoming film. "I would love Harry to do it, but I can't imagine him getting into that kind of role. He is too sweet to play him," she said. "Douglas Booth is my other dream cast. Indiana Evans was cast as Tessa when I was writing the fan fiction on Wattpad, so that's whom I would want to play Tessa. However, I trust the producers to pick the perfect Tessa."