Wang Shiang Shiang and Chow Nuo Yan were students of Heng Shing Secondary School in Sun City.
Two years ago, Shiang Shiang's grandfather, Wang Ting, had a brain surgery done at Moon City. If the operation was successful, he would be able to keep his memories; but if the operation failed, he would lose them all. However, Wang Ting lost all contact with his family after the operation. Shiang Shiang missed him very much.
One day, Shiang Shiang saw her grandfather's photo in a shop selling puzzles at Sun City. After some investigations, she found out that the person in the photo was called Wang Shin, who was the grandfather of the owner of the shop, Jyun Yi. Wang Shin was not only identical in appearance to Shiang Shiang's grandfather, his personal habits and likings were also similar! However, Wang Shin treated Shiang Shiang like a total stranger; he had no impression of Shiang Shiang at all. Meanwhile, Shiang Shiang received an anonymous note, warning her not to investigate further, or she could face terrible consequences…
Who was that Wang Shin that was a splitting image of her grandfather? Was he her grandfather who had lost his memories? Who was Jyun Yi? Who warned Shiang Shiang against looking further for her grandfather? All these questions made Shiang Shiang more eager to find out the truth.
This time, Shiang Shiang, Nuo Yan, and their best friend Shuan Er who was studying overseas put their minds together, showed the power of their friendship so that they could find out the truth.