What Should I Do If My Sister Is Reborn?

Sixteen-year-old Li Hansu has always believed that if he fell into the darkness, all he could do was wait quietly until his eyes adapted to the darkness. It wasn't until he met a lonely girl that he discovered that loneliness is a salvation. One day his sister is reborn and tries to pull him out of the darkness, but little does he know that he will fall deeper into the quagmire.