It all started when they were around three years old. Roy's parents and Kathrine's parents were the best of friends, so of course they grew up together. As they grew up and went to school, they kind of separated and made other friends, but they still hung out occasionally. When Roy started his singing career, he had to leave home sometimes and travel with the other TFBoys. However, as time passed, they began to talk to each other more and more again, though usually through texting or on the phone. Now, Kathrine is 17 and Roy is 16. They're back to being best friends, although they like to keep the friendship on the down low (due to some obsessive fans). Now on Karry's 18th birthday, the TFBoys are doing a special tour around China, making sure to be in Chongqing on his birthday so they can host a private friends and family only party.