Kai's family has dedicated their whole life to painting. 

His family consisted of him , his older brother , Kyungsoo and his younger brother , Luhan.

When one day , Kai somehow accidentally found out that he was adopted , he is deeply upset , although Kyungsoo keep telling him it makes no difference at all. Kai is the son of his 'mother' 's twin sister , who lived in the more western part of the country , and died in a shipwreck.

His uncle bought Kai , as a very small child , to his aunt's house , away from his real house.

At his uncle's death , he left something for each of the children , for Kai , it is his 'Angel' although no one knows its identity.