Kyeong-joon is driven out to the streets as he can't afford the rising rent. His girlfriend Ji-hye takes pity of him as he has nowhere to go and offers him to stay at her house. However, the woman who greets them at the door is his first love Ji-yeong! Ji-yeong taught Kyeong-joon about love and she was Ji-hye's step-mother. Living under the same roof, he feels something for her again while his girlfriend is also hot.

Crystal remarried to husband with son. She's just a little bit different. She's trying to get along with her son Sewoong, he doesn't easily open his mind. One day, Se-woong and Dad's friend witnessed the cheating scene. After that day, whenever she sees a crystal that is lonely without her husband, it's starting to look like a woman...

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.