She is an actress.. he is the pretty boy from the band. She has secrets.. he is an open book. When fate brought them together.. they thought the feeling was temporary. 

Ji Hyo is well known as the 'Ace' of Running Man and through her leading role in romantic movies. Everytime she paired with famous actors, her fans are hoping for her to be in a real relationship with her co-stars. But being in a reel relationship makes her believe that to love is "her job".. and she is professional about it.

Joong Ki and his band "HeRoze" know what the fans want.. a group of good-looking man performing songs that will melt their heart and lyrics that are beautifully written for those who believe in love. The reality is.. Joong Ki can only expressed his feeling through his music. He never want to be in a relationship - afraid that his popularity will be affected and he no longer be the favourite member of his band. 

The moment Ji Hyo and Joong Ki were chosen as the main casts for an upcoming romantic movie.. they soon learn the real meaning of "falling in love" for the first time. But does the chemistry of song-song couple be stronger than the powerful SpartAce of Running Man?