Zou Yuan is an ordinary high school boy who lives alone and leads a peaceful life. One day, he suddenly receives a huge parcel, which contained a crystal cabinet, and inside the cabinet was a beautiful girl! The girl's name is Xue Ye, and she comes from the future. The Earth in 2398 AD is a world devastated by nuclear war. The survivors of the nuclear war lived in the underground city built by Xue Ye's grandfather and they were trying to rebuild their lives. However, a gang of criminals who escaped from the prison of Exile Star showed up and tried to take over the underground city and seize the time machine invented by Xue Ye's grandfather, intending to wreak havoc across time and space. In order to fight off the gang and save the underground city, her grandfather sent Xue Ye back through time, hoping to go back to 2014 to seek the help of the brilliant scientist named "Zou Yuan." However, due to a malfunction, she mistakenly fell to 1994 and found the 15-year-old Zou Yuan instead. What's worse, several criminals from Exile Star also tracked Xue Ye through the time machine. Now Zou Yuan and his friends must work together to protect Xue Ye and fight off the criminals…