Iu should refer to IU, the stage name of IU is IU, "I" refers to himself, "U" refers to his fans, and the aid slogan of IU is "milk luster IU".

"Cream Light IU" probably means that I hope to be with fans who like me forever, and I also hope that my singing can make people who listen to songs sing. The name of Korean fans is U-ana(Uaena).