Yu Dongqing and his wife Yao Fengqin first began exchanging love letters when they met in 1978, the same year that China's reform and opening-up began. Their correspondence, which continues over 40 years, captures some of the incredible changes the country has experienced.
Their story began at a chance encounter at a platform at a train station, where Yu fell in love with Yao at first sight. He changed his national food stamps into meal tickets to eat at the girl's college.
Finally, they got married and had a home of their own. And throughout the years, their affection continued as they had lots of joyous and difficult moments.
The couple also witnessed the country's changes, from watching their daughter volunteer for the Beijing Olympics to marveling at the beautiful photos on the occasion of her wedding.
In their retirement, they see their grandson growing up in a world of high-tech wonders, from high-speed trains to digital media, and envision the possibility of traveling overseas.