WM Entertainment's new boyband, 'B1A4', has been headlining for their unique webtoons concept, which later opened up to individual member teasers that aimed to showcase the charms of the group. After much anticipation, the group has finally unveiled the music video of their debut title track, "OK". Check it out below, including tracks from their first mini album, "Let's Fly": Remember 못된 것만 배워서 Bling Girl Only One === The boys will be making their official debut on April 21st, and if you missed the individual member teasers, check them out here: Baro, Gongchan, Sandeul, CNU, and Jinyoung. Source: B1A4 Official Site