When he was 7 years old, he made a vow to her. That was the best memory of her life. When she was 12 years old, she lost her memory because of the jealousy of her younger sister Xia Zhiyu, and also lost the best memory in her life. 3 Years later, she met him and he still remembered her. She——is Xia Zhiqing. He——is Kikumaru Eiji.