男主有勃起障碍，跟女主结婚好几年了一直无法勃起，想尽了各种办法依然不行，某一天好友突然打来电话，说是生意破产了，想来家中住一段时间，好心的男主收留了好友，好友便带着自己的妻子一起前来，好友妻子的美艳吸引了男主，男主的下体竟然有了反应，男主的妻子也很高兴，觉得有望治疗男主的病了，于是她决定做出牺牲，通过换妻来治愈男主....

韩国限制级，讲述课堂上的两人的私密关系....

男主生意失败，无处居住，搬去了妻子娘家居住，由于岳父岳母已经离婚，男主的新岳母很年轻，同样也欲求不满，男主整天忙于生意，冷落了妻子，妻子便也有了外遇，跟外面的男人整日厮混，男主从妻子那也得不到性满足，更是心烦意乱，这一切被小岳母收于眼底，为了缓和家中的气氛，她想到了一个用自己的肉体来使男主放松下来的妙计....

It's not...something you should say... You always bring women home... Jeong-soo is far from getting his grades up after he breaks up with his girlfriend so his father gets him a tutor (Yoo-jin). Let's go to your room to study. Jeong-soo thinks Yoo-jin is just one of his father's many women and she approaches him with kindness. Ordinary love...like everyone else.... Jeong-soo wasn't good at ordinary love and starts getting special lessons from Yoo-jin. As they get closer, he feels something lingering in his heart...