Meanwhile his previous film, Kwon Yong-kuk's The Elephant On The Bike, saw him playing an internalised, quiet part as a physically challenged young man.
'The character is totally crazy,' Yang says of Seven Days. 'He goes straight from laughing to crying and drooling saliva, and the director was demanding about it all, but great to work with.
'I've always been attracted to that part of acting that lets you experience different worlds,' says the actor, who graduated from university in Australia with a double degree in international business and broadcast media.
He found the thought of a regular job unappealing, 'so I decided to take a shot at this adventure, this childhood dream of mine. I just came to Korea and in a month or two I was at iHQ.'
After seven or eight months of acting classes, he auditioned and won a part in the SBS drama Great Aspirations. His first film experience was Once Upon A Time In A Battlefield (2003) by director Lee Joon-ik, who later made the record-breaking hit King And The Clown.
'He was the best, and so were the staff and my fellow actors,' says Yang. 'That's when I first met [veteran actor] Jung Jin-young, who taught me a lot about acting.
He's the person I most respect, and would love to act with him again.'
Yang then appeared in the television series Magic, and went to Japan for the drama Promise.
His one year in college as an exchange student in Japan helped with the linguistics, and he gained a fanbase there.
Yang is also fluent in English and says he wants to work on foreign productions. 'I'm working on my American accent these days,' he says with a smile.
'I would ideally like to star in something that deals with subject matter that hasn't been done before,' he says. 'Something unique the way Taxi Driver was, that has a new and different kind of character. Directors like Jang Joon-hwan, who did Save The Green Planet! or Christopher Nolan would be fascinating to work with.'
Contact: iHQ, (82) 260 056 005
The Elephant On The Bike (2007)
Dir: Kwon Yong-kuk
The Evil Twin (2007)
Dir: Kim Ji-hwan
Dharma 2 - Showdown In Seoul (2004)
Dir: Yook Sang-hyo
Seven Days (2007)
Dir: Won Shin-yeon