Ruin Me? Then I Marry Your Worst Nightmare Manga

Colin is the adopted child of the Bishops. He is engaged to Jenna, yet she and his brother Kyle drug him, and he sleeps with Aman, CEO of Empire Group. Jenna and the Bishops then kick him out, leaving him defamed and destitute. Aman comes to his help. They crush the Bishops together, and come to form a real marriage. Not as a deal, but as a promise.