H.U.B (stands for Hope U Bounce) is a five member girl group under New Planet Entertainment.
Before the group debuted Rui debuted on 2016 as a soloist with "Exciting".
Originally H.U.B was conformed by four members, Keina, Gracie, Rui and Yeum . They released the pre-release single "Our Time Together" on November 24, 2016.
The group officially debuted on February 9, 2017 with "Girl Gang" also called "Girl in Black". It has no music video and was written and choreographed by the members.
On May 31, 2017 was announced that Hyosun (a contestant on Produce 101)
was going to be added. A day later the released "Ooh Ooh" but Hyosun did not participate in it.