iKON's B.I, ONE, and YG Entertainment�trainee Choi Raesung (MILLENNIUM) have revealed an unofficial collaboration on Instagram.

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Fans noticed the video posted to ONE's private account with the caption, "This world has just the two of us, and I hope it's special." In the clip, the three take inspiration from retro music videos as they perform on a rooftop for their unofficial indie tune.

Check out the music video, and let us know what you think in the comments below!

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A post shared by @onlyoneprivate on Dec 13, 2017 at 9:42pm PST