After Wang Shiya and Bai Hu perished in a factory fire, their orphan, Bai Shengqi, was left behind.
Su Dongkun originally intended to adopt Bai Shengqi, and marry him off to his own daughter.
Bai Shengqi carried the blood of Wang Shiya, and his daughter carried his, Su Dongkun's, blood. If the two of them were to procreate, their child would continue his and Wang Shiya's bloodline, giving him a perverse kind of satisfaction.
Unbeknownst to him, Dong Zhenghong beat him to it and adopted Bai Shengqi. Both Su Dongkun and Dong Zhenghong had admired Wang Shiya in their youth. Dong Zhenghong even proposed to Wang Shiya, but she didn't like him and chose Bai Hu instead.