QBS was the second official sub-group of South Korean girl group T-ara based in Japan, with composed of three members: Boram, Qri and Soyeon. The trio only released one single, "Kaze no Yō ni" (風のように, "Like the Wind") in June 2013.
In April 2013, T-ara N4's member through their press conference announced that the remaining members of T-ara: Qri, Boram and Soyeon would prepared a Japanese sub-unit.[1] [2] The sub-group focuses on the Japanese market, and released their debut single on June 26, 2013.[3] [4]
In May 2017, Boram and Soyeon's exclusive contract had expired with MBK Entertainment and also left from T-ara, which also effectively the trio's disbandment.[5] [6]