Responses
This one???
http://www.mangago.me/read-manga/love_stage/
Love stage is the name pf the manga ;)
This is from the manga called Love Stage which also has an anime adaption. The Bro and Secretary yums yums is in a spin off called Back Stage.
Looking for a the one where he played a girl in a commercial and the lead boy fell in love with him. Also the brother is in a relation with his father secretary. They are a showbiz family