Oniisamakata, Goranshin!

The eldest son, Yukiya is a man who wears glasses and has gentle manners, but is a SM fiction writer. The second son, Kousuke, is a handsome youth with a childlike face, but he is the number 1 host. The third son, Masaki is an extremely popular idol, but he is ill mannered and like to tease everyone…and these three older brothers dote the youngest child, Miyuki with excessive care. Trying to escape from their constant interference she creates a plan but…!?

(Source: Chibi Manga)