Somehow related in a way that it was all about a boy and a girl that they said was in a relationship of a brother and sister who later revealed that they weren't. And later, fell in love w/ each other.. :D
Both of these mangas deal with singers who meet a high school girl outside of the showbiz world. The singers are different then the way they act on stage. The girls have to deal with the difficulties of loving someone in a world a part.
It somehow has the same story but not the whole of it. Both have a celebrity being a relative to the girl and also the celebrity being their idol. Also that the idol seem to have a different personality off cam..