B1A4 (Korean: 비원에이포) is a South Korean idol group under the management of WM Entertainment. The group debuted in 2011 with the single "O.K" after their first introduction to the public through a webtoon. They have released two studio albums, five EPs and various singles in South Korea.
The group began their foray into the Japanese market late 2011 with a showcase and in 2012, they released their first compilation album that consisted of all the tracks from their first two EPs Let's Fly and It B1A4. The group released remakes of two Korean singles, namely "Beautiful Target" and "Sleep Well, Good Night", as Japanese singles on June and August respectively, both peaking at number four on the Oricon weekly singles chart. Their debut Japanese album 1 was released in October 2012, with its music video released by Pony Canyon.[1]