Kim Soo-jin, the woman who opened my eyes to the castle! But as soon as she enlisted, she put her rubber shoes upside down… And with the huge US Army..!! She can't forget her hot night with him. Suddenly, he became the troublemaker of his unit and a soldier of interest. Then one day, So-Hee's older sister, whom she had a crush on when she was young, began to visit her. Became her older brother's girlfriend… !!