It has been almost 4 years since they last met on the set of highly popular K-drama, Master's Sun. Many viewers have thought that they were the ideal match as they witnessed a cheerful So-Ganji and a blushing Gong-Vely on national tv. The endless laughing, teasing, and skinship on and off scenes was enough to make anyone wonder about their true relationship. 

With both of them famously single, and the astonishing fact that how the introvert So Ji-sub could click with the extrovert Gong Hyo-jin at the snap of fingers and was seen to be having a blast of his time with her, sent tongues wagging. Even the staff on set had likened them to be a real-life couple because of the little fact how easy Gong Hyo-jin could make So Ji-sub laugh and relax around her like never before.

To the onlookers, the two of them have generated enough heat on set to set off the potential couple alert alarm in everybody and they were simply waiting for the alarm to trigger anytime on the news. "No non-couple could behave the way they did without interest, they are simply avoiding the unavoidable for the sake of the drama ratings," everyone was convinced that they were a sooner or later couple anytime. 

But 4 years down the road, the ideal couple never got together as predicted as Joon-won and Gong-shi left So Ji-sub and Gong Hyo-jin. The intense chemistry and crackling passion between the couple were rudely cast away by two professional artistes but never forgotten. Somewhere along the path to their passion discovery, it became an unmentioned hide-and-seek game, with no one that brave enough to end this game or regret.

So Ji-sub would have continued ignoring the emptiness in his heart if he had not met Song Joong-ki, the young male who is fearless in his persuade for love and causing a Hallyu meltdown with his announcement of marriage to another top star Song Hye-kyo. Song Joong-ki has shown everyone how determination and passion could overwrite all the unwritten rules about co-stars romances, giving hope to many other potential on-screen couples to become real. 

It was the spark needed to push So Ji-sub into action once again, in search for his Taeyang in their game of hide-and-seek again.