Young-suk's father, Dae-sung, is the one who will soon become your stepmother and introduces Hitomi to Young-suk. Hitomi is a young lady of twenty-five who is two years younger than Youngsuk. Young-seok's younger and sexy stepmother Hitomi keeps beating more and more. Then one night, Hitomi comes into Youngsuk's room and takes off his pants...?! Dad begins a breathtaking double life with a Japanese mother you should never know.

"Innocent face, D-cup breasts and perfect intercourse skills! Son, this is not your girlfriend anymore but your mother!" Ki-ho brings Yuki from Japan to marry her. However, he starts cheating on her with his ex-girlfriend in Korea. Min-cheol comforted Yuki and thought of her as his daughter-in-law, but one day he realizes he is looking at her as a woman. In the end, Yuki and Min-cheol have intercourse without Ki-ho knowing...