I'm looking for a story that I read a lot of time ago... is about a guy who is the company's president son and is in love with his father's secretary. The father dies and he inherits the company and his father 's secretary but he believes the guy hates him. Later he discovers that his father was abusing of the guy and the guy wasn't really his father lover as he thought, but a victim of his father.
Does this description rings a bell to someone?
Thanks in advance!

Itsuwari no Daishou

Yes! That's it!
Thank you so much!