Love Stage!!

With a father who's a singer, a mother who's a movie star, and an older brother Shougo who's the lead vocalist for the super-popular band "The Crusherz", Sena Izumi—an otaku college student—is the only dull one born into this super-famous and talented family. He loves "Magical Girl LalaLulu" and is working hard to become a mangaka, but one day he winds up appearing in a TV commercial he just can't turn down. There, he's reunited with Ichijou Ryouma, the super-popular young actor he costarred with on a project ten years prior.

(Source: September Scanlations)