Syong Dee-a is at first quite ordinary. It's not scary like those creepy ghosts. But it gradually seeps into the feelings. And the level of syong (fear) will gradually increase as you keep reading.
As you progress through the story, you start to notice the little details that build up the sense of unease. The atmosphere becomes thicker, and your heart might start to race a little.
It's that kind of slow-burning horror that catches you off guard. You think you can handle it at first, but before you know it, you're completely immersed in the world of Syong Dee-a and feeling the full impact of its terror.