The story mainly tells about a high school student named Haitang Qing who was deceived by the news that her mother was dying and went overseas. There, she was suddenly introduced to a man named Zero, who was her younger brother! Qing desperately took care of the wild boy Zero who didn't listen to anyone. Zero's life experience seemed to be a secret. In addition, when Zero finally began to get close to her, a tragedy happened to Qing. Five years later, what kind of life will Qing face after meeting the grown-up Zero again?