Sister Han Dangwu was murdered several years ago, and the murderer is still at large. Brother Han Yibai never cares for his sister and often quarrels with her. Until an accident happens, he travels to the future five years later and obtains a mobile phone and his sister's diary. Through the phone, he gets in touch with his sister who is still alive. And helps his sister successfully avoid crisis after crisis. His sister has invisibly influenced his future destiny... When bringing the murderer to justice, the brother tells her that the murderer is someone else...