B1A4 (비원에이포) or ‘Be the One All for One’
is a boyband from South Korea under the auspices of WM Entertainment. This group was initially introduced through an online comic series, or ‘webtoon’. B1A4’s name also taken from famine blood group members is 1 blood type B and 4 blood type A. B1A4 debuts on April 21, 2011 with the track ‘O.K’ from their album ‘Let’s Fly’ and released a music video. They made their live debut on 23 April 2011 on MBC’s Music Core.