After taking the Cannes Film Festival by storm in more ways than one, Netflix’s latest original film Okja is available on the subscription service this week. To celebrate its release, we spoke to its creator and director Bong Joon-Ho and star Seo-Hyun Ahn about the film.

The idea of Okja has been floating around the director’s mind for a few years now and while he was preparing the script for his previous film, Snowpiercer, it hit him in a strange way:

“It was 2010 during the screenwriting phase of Snowpiercer. I was in the middle of Seoul – huge place, 11 million people, too many people! – and I was driving in the middle of the city, suddenly it just hit my mind, the image of a huge animal. Originally it was much bigger than what you see in the movie too. Almost 30ft high but her face looks very shy and sad and introvert. So that was the beginning and I kept thinking ‘Why is she in the middle of the city?’ and what happened to her to look so sad, who makes her so sad and who loves her.”

The film has been made for Netflix, who are slowly and surely becoming a big player in the film world with this, Brad Pitt’s War Machine and Bright, starring Will Smith, all debuting on the service this year. Joon-Ho said that any studios balked at the film and the costs, but Netflix and indeed Pitt’s production company saw its potential. Joon-Jo recalls:

“The process was first to have a package – me, screenwriters, effects company, Tilda, Jake, Paul – and then we looked for the main financiers. And from that process Plan B (Brad Pitt’s production company) and Netflix came to us. Many studios hesitated because of the, in their expression, ‘idiosyncratic script’, a word I didn’t know at the time, and some independent financiers who loved the script a lot but for them, the budget was far too big, because of all the effects it was over $50million. It was quite tough but Netflix had the money and are also very respectful to the creators so we were very lucky and because of them I got to make the movie.”

Seo Hyun-Ahn and Bong Joon-Ho - Okja

At the forefront of the film alongside Okja is Seo Hyun-Ahn, the teenage star of the film who was immediately the choice for the lead character of Mija from the outset. Joon-Ho says that it was her fearlessness that won him over, saying:

“Specifically it was the unstoppable energy that she possessed. In films like King Kong, it’s the ape that protects the woman but in this film, she is the one who protects Okja so what we needed for Mija was a strong sense of strength and that energy. In her previous films, she was always cool and natural and simple – her work is never overdone it’s just simplistically appropriate.”

Okja is a strange film in terms of its story (large pig-like creature running around Korea and New York) but it was the combination of the strange aspects of the script that Hyun-Ahn was first attracted to. She said:

“When I first read the script, I felt this was a very creative and strange film with aspects that might not naturally come together would create a harmony in a very interesting way. Mija is not just a typical ‘girly-girl’ and Okja is not a typical ‘scary’ creature and that odd mutual harmony that Bong created made me really want to do it.”

Visually, Okja is a wonder and not least the creature itself – a looming, large figure, it was a huge challenge for Joon-Ho and his team both figuring out how the actors would integrate and act with only small reference points but also how Okja would look once the computer wizards started work. Thankfully, they had the help of the same CGI genius’ who helped bring Life of Pi to the screen. Joon-Ho says:

“It was really challenging because we had to create a very strong bond between Okja and Mija, an intimacy. Usually, it’s a big creature attacking a city but here they sleep together and always touching so that was the most challenging part for me and Eric de Boer (effects supervisor). He did the effects for Charlie Parker in Life of Pi – he’s a genius and for 24 hours he is thinking about animals, he knows every small part of Okja, from the skeleton, the muscles and skin and he’s like an actor himself because he is able to create so many subtle nuances of emotion from Okja through the movie and that’s all him. We had a reference puppet that’s made of sponge and fiberglass that replicated Okja, the same size, and everything.”

Seo Hyun-Ahn and Bong Joon-Ho - Okja

Despite acting alongside a “fake” Okja, which she does phenomenally well, Hyun-Ahn spends a lot of the film running to save Okja before she is set upon by the evil corporation intent on using her against Mija’s will. She’s certainly an energetic presence in real-life too and when asked about giving Tom Cruise a “run” for his money in the sprinting stakes, the actress says the hard running she left to the stunt people, saying:

“I went to action school months before shooting to practice. I practiced a lot but on set I only did a little bit of the running but there was a very steep cement hill that I had to run down which was really difficult but thankfully I didn’t have to do any of the really hard running!”

Okja arrives on Netflix on June 28th.