I don't care if it's gay or straight etc.
the situation must be : the male lead is a ceo/business man etc. and falls in love with the female lead. AND the male lead's secretary / assistant falls in love with the female lead's friend/family member.

bump

Maybe you will like it - "Midnight Secretary" by Tomu Ohmi: This manga follows the story of Kaya Satozuka, a capable secretary who is assigned to work for a mysterious and handsome CEO named Kyouhei Touma. As they work together, a romantic relationship develops between Kaya and Kyouhei. While the specific situation of the male lead's secretary falling in love with the female lead's friend/family member may not be present, the manga still offers an office romance theme.

Don’t believe in the me that believe in you, don’t believe in the you that believes in me, believe in yourself who believes in you!