Japanese actor Takeru Satoh plays an Ajin, an immortal creature in the live-action flick Ajin: Demi-Human, but he feared for his life while filming the movie.
He says in an e-mail interview: "My character, Kei, is someone who is constantly being chased, falling down and having things happening to him, and I finally understood how action scenes can really take their toll.
"After falling off a high place more than 30 times in one day, my neck shrank by 2cm. I really thought I was going to die."
Satoh, 28, plays Kei Nagai, a hospital intern who realises he is immortal after a traffic accident. He is captured by the government and subjected to a battery of brutal tests before getting rescued by a fellow Ajin, Sato, played by Go Ayano. But Kei objects to Sato's violent ways and the two immortals find themselves headed for a showdown.
The film is in cinemas.
Another power that the Ajin have is the ability to project a creature outside of themselves that is made of Invisible Black Matter. Kei calls his a "ghost" and while they are not quite solid, they have a mind of their own and are able to inflict real damage.
As the "ghosts" were fully computer-animated, Satoh says: "There was nothing in front of us when we were acting. I had to use my imagination and was never really sure what was happening at any point."
Because of the physical demands of the role, he had to be in good shape. He decided to follow Ayano's example of sticking to a diet. And then, some of the crew started to get in on the act.
Satoh says: "(So) it wasn't like the usual (shoot) where everyone goes out to eat a good meal together, but that everyone was eating the same salad and boiled eggs."
The actor has been on a roll in recent years with leading roles in several big-screen manga adaptations, including the period action Rurouni Kenshin trilogy (2012 and 2014) and Bakuman (2015), about the life of manga writers.
The challenge is always to please fans of the print work while making the adaptation work as a movie.
He says of the approach: "(We) strive to reproduce the worldview of the original work while borrowing the story setting only.
"I always make the most of the story setting and keep in mind the fact that I want fans of the original work to think that the live-action film is interesting."
Hence, the idea for Ajin: Demi-Human was to create action that had not been seen before in other movies.
It helped that it was the same stunt team from the Rurouni Kenshin films, "so there was already a level of trust established", Satoh adds.
And while the neck-shortening action scenes were tough, he sounds as though he had no regrets doing them.
He says: "We need to do justice to the film for the audience who would be watching."
•Ajin: Demi-Human is showing in cinemas.