Ah yes, B1A4, the blood types of the group members: 1 Type B, 4 Type A. This song is one amazing little gem, released in 2011 and instantly becoming one of B1A4's signature tracks. The music video is mad - it barely makes sense. The English (or Engrish as I like to call it) is catastrophic. But I love it all the same because it's so mad and happy. Watch, enjoy and wonder what "joom joom my heart like a locket means". I know what it means, but will you? Enjoy!