South Korea's pop idol drops the love songs to star in this R-rated made-in-Berlin bloodbath.

Rain is presented as 'Raizo' in 'Ninja Assassin' who is an orphaned boy in a remote monastery-style complex who trains under a grandmaster with sadistic tendencies. He learns the art of killing and enduring extreme physical punishment.

The movie begins with Raizo becoming a revenge seeking rogue while protecting a Europol agent.

Rain was selected personally for this particular role by producers the Wachowski brothers when he was filming their "Speed Racer".

Rain who is 27 years old trained in dancing and not martial arts. "I wanted to challenge myself, to find where my limit is," he said. "I had all the stunts, there's no wire, no camera tricks. No green screen. We had classic filming. It was real."

He said that his moniker was given to him when he was 10 and just started his whirling-dervish dance moves.

Rain said that his heroes are Jackie Chan, Bruce Lee and Jet Li but also showed confidence in his strength, face and youth.