In the summer of 2006, poor student Lin Mingkuan (played by Zhang Ruijia) saw Chen Wenqing (played by Lin Yixin), the first place winner of the Taiwan Piano Competition, on the Internet and fell in love with her. Then A Kuan met Xiaoqing who came to Kinmen for summer vacation. By chance, the two met. That summer, A Kuan and his friend Sha Chong (played by Li Jiawen) took Xiaoqing to travel around Kinmen. They saw the beauty of Kinmen under the sun and the stars, and also felt the sweetness and bitterness of first love. Xiaoqing likes to take pictures with her mobile phone, and all the profound pictures are recorded in her mobile phone. When Xiaoqing practiced the piano every day, A Kuan listened outside the house. That was his happiest moment every day. Xiaoqing spent the best summer vacation with A Kuan and promised to send A Kuan an e-mail every day after returning, and also promised to return to him next summer! From then on, receiving e-mails every day was what A Kuan looked forward to most. The piano sounded again in the summer of the second year, but A Kuan felt that this Xiaoqing was different. Until one day, A Kuan and Sha Chong passed by the cemetery and saw Xiao Qing's tombstone. The date of death was October 18, 2006. What was going on? Was it a prank? Or did Xiao Qing come back to keep her promise...