When he meets her again, can he still recall Zongzong when he was a child? Will you still remember everything you promised? It was not realized in the end. He kept remembering it, so he came back. He wanted to ask clearly why she didn't come that day, why she never called him, why... Why I didn't recognize you when I met you, why I fell in love with a woman I couldn't love, and why did you have to be my sister?