Deceptively simple but clever plot. Movie is extremely well paced and highly entertaining. Never a dull moment. Yoo Yeon Seok's playboy character was very well written and he played it well. While boldly declaring his sexual attraction to Moon, who was a stranger on the train, Yoo was cheeky yet oozed charm throughout the journey, without coming across one bit as a creepy, sleazy predator. It was hilarious watching him played cool as a cucumber while Moon was desperately trying to thwart his smooth advances.