friendship. Because Kevin·Z and Huang Yubo knew each other when they were very young, and they both filmed "Star Elf Lan Duo Duo" and "Alien Boy Duo Bu Duo" together when they were young, and they were admitted to the same university after they grew up, named Nanjing Art Institute, and Kevin·Z also appeared in Huang Yubo's music mv, so Kevin·Z and Huang Yubo are friends.