Luc Besson has revealed he had to win over "grumpy old man" Jacques Tardi before he would allow him to adapt his comic books The Extraordinary Adventures of Adele Blanc-Sec for film.
The Fifth Element director was a huge fan of the comics and admits adapting them for the big screen was a "lazy" and "fun" job for him, but getting the characters' creator to sign over the rights was much harder.
Luc said: "That was more difficult because he's a grumpy old man and he doesn't want to give his daughter to anyone.
"So I had to be very patient and he has a couple of experiences of people, American, Japanese, French, who want to do films with her and it was always like a catastrophe with him and so he doesn't want to hear about cinema any more, he was mad to everyone.
"And so it takes time to pretend I'm different and I think he wants to be sure that we will respect Adele, the way he thought about her. I was very faithful and I think it takes him a couple of months to measure that I was really loving her. So he gave me her hand."
Despite there being more stories at his disposal Luc insists he hasn't begun work on a sequel to the film, released on Friday 22 April and starring Louise Bourgoin and The Diving Bell and the Butterfly's Mathieu Almaric as Adele's nemesis Dieuleveut.
Luc said: "You can't make a sequel if the people don't enjoy the first one.
"So we have to humble and realist and show the first one and if everyone likes it they can write to me and say 'We like it, make another one'.
"But for now nothing is written."