SISTAR's Bora tweeted in support for her labelmate hoobae Boyfriend.

She tweeted, "You guys are men!!! My Boyfriend dongsaengs are coming back with "Janus"! Do~ well!! Aja >.< But... who's... Youngmin, Kwangmin. Nuna can't tell! ?.?", and attached the link to Boyfriend's YouTube teaser as well.

The boys of Boyfriend have been teasing fans with a series of images for their comeback song "Janus", and have released a video teaser. The teaser features the twins Youngmin and Kwangmin as well as a new Starship Entertainment trainee.

Source: SISTAR's Twitter