Your brother died in the school, and you decided go to his school and infiltrate like a student more, no one knows about you being brother of Han Jisung, so when you arrive you know Hyunjin, he is serious and he has a cerebral tumor, so he changes attitudes being violent, two weeks later now your living with him because you were rejected in you apartment, you know about his cerebral tumor but you don’t say you know, when Hyunjin knows your brother is Han Jisung he says: “I saw him die.”