Thirteen-year-old Wang Yiran has a piggy bank.<br /><br />What she saves in the piggy bank are not coins but letters of regret from her parents who have to work overtime as train crew in China's Shanxi province.<br /><br />WATCH MORE: https://thestartv.com/c/news<br />SUBSCRIBE: https://cutt.ly/TheStar<br />LIKE: https://fb.com/TheStarOnline
