They are brother and sister. Her parents died in an accident and she was adopted by his parents. She has liked him since she was a child. She always followed him and called him: "I don't know, brother." He annoyed her at first and always called her a fool, but later it became a habit. Later, she tried her best to get admitted to his university, but found that he already had a beautiful woman by his side. She smiled bitterly: I don't know, I was late after all. Later, when he went abroad, she discovered a shocking secret at home. When he came back, it was too late. . . .