The song you are looking for, "What Should I Do" (also known as "What to Do" or "What Do I Do"), is a central track from the 2009 Korean drama You're Beautiful . It was famously performed by both lead actors, Jang Keun-suk Park Shin-hye , as well as singer Park Da-ye Where to Listen and Download

Apps like JioSaavn often provide options to purchase and download individual tracks or the full album.

You're Beautiful (Music from the Original TV Series) - Spotify