"Behind your Smile" is a thriller with romantic elements, just like WTPR. The ML in this story is like Baek Sa Eon rather cold and dark. However, he is obsessed with revenge and wants to get back at the FL who is very innocent and naive. Their relationship slowly changes. The drama is mainly carried by Marcus Chang's acting and his amazing chemistry with his co-star.

Similar to WTPR, in this drama, FL takes on the role of her twin sister after she disappears. Therefore, she is forced to play the fiancée of her sister's boyfriend, but she is already making plans to escape. Compared to WTPR, it's more of a light romcom.