On October 7, 2015 the group's official website was created and their first extended play, "The Story Begins", would be released with the single "Like Ooh-Ahh" which was released on October 20. On the same day as their EP's release the group performed all tracks at a live performance. The music video was watched 50 million times on YouTube within five months of it's release and became one of the most-viewed debut music videos of any K-pop group. The group performed "Like Ooh-Ahh" at "SBS Gayo Daejeon" at the end of 2015.