Seok-jin has a tremendous amount of energy. Mi-sun introduces her friend Hyun-jung to Seok-jin, who will be the very father. Hyunjung, who had no place to stay, stayed at Seokjin's house at the request of Misun. Hyunjeong is twisting Seokjin. After having sex with Seok-jin, Hyun-jung says that it was too good for Mi-sun. Mi-sun approaches Seok-jin as a substitute for Hyun-woo, who is the best. Seokjin also enjoys sex with his sister's fiance, Misun.