While living at the orphanage, a young boy was relentlessly bullied by both his peers and the teachers, leading him to the brink of taking his own life.​However, a girl entered his life and gave him hope to keep living.​"Noona..." (or "Big sister...")"Yes?""When we grow up, will we live together?""Of course. We're going to live together."​She was his absolute everything.​Then one day, an opportunity arose for a wealthy family to adopt him.​"Noona, I don’t want to go! Please... I just want to stay with you!"​No matter how bitterly he cried, they carried him away to be adopted.​"Noona, save me! Please help me!"​He couldn't even catch a glimpse of her shadow as he was taken.​From the moment he was separated from her, his life turned completely hollow and desolate.​"I will find you no matter what, and I will make you pay for all the loneliness I suffered.""I will keep you by my side forever.""Anyone who tries to interfere... I'll kill them all."​"I'm sorry...""I really don't remember anything from our childhood.""I already have someone I love. Please let me go."​"What?! Don't say that! You're only allowed to love me!""You said I was your favorite back then!""I won't even tolerate you having other friends.""Instead of having friends, just love me more!""Listen, if you ever try to leave me, don't blame me for what happens next."