It's more a thriller than an horror movie. I think you shouldn't read any summaries because it explains too much of the plot and you will find the movie boring if you know everything from the start. The storie is interesting and you want to know what happened but it's not really frightening so don't be abused by the poster :p
Smile you (he was soooo cute <3)
I've seen him in so many other dramas Oo there's "Hero" where he have the main role for exemple