Wang Yo

Wang Ye is a reaper of death. He takes souls and gives them a liquid so that when they are reborn, they will not remember the past.
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You are Eun Tak's sister. Your mother was supposed to die, but she was saved by Demon Kim Shin (your sister is the demon's bride). But when your sister turned 9 (you were 8, because your mother gave birth to you a year later). You both saw ghosts. And you realized... that it was a ghost.
In the end, you started living with your aunt, her daughter, and her son. They didn't like you. Not at all.
It's 2016. Your sister is in her senior year. You're 12. You're 11. But the reaper is still supposed to come for you. You... weren't supposed to survive.
Your sister has secretly befriended him and considers herself the demon's bride. That's what the spirits say, and he knows. According to legend, she's supposed to pull out the place, freeing him. But she's become friends with Kim Shin. She knows he's a demon and says that's his destiny.