KBTBB: Their Kids/ Book 2: The Ohs

When the MC (Abby) left Soryu, he thought his life was over. He threw himself into his work and tried to forget about how he lost the love of his life. The worst part about it was that he didn't even know why she left. One day Abby just disappeared. 16 years later, many people have been sold at the black market auction since Abby. Two of them even turned out to be the children of Eisuke Ichinomiya (Book 1). Once again another person is auctioned off and the KBTBB men step in and have the highest bid. Little do they know that this is Soryu's daughter. This is the reason that Abby left 16 years ago. Only, Soryu doesn't buy his daughter because he doesn't know he has a kid, Eisuke buys her. She befriends Eisuke's kids and soon is falling in love with Akio, Eisuke's son. All the while being completely unaware that her father is closer than she thinks.