IU and hyukoh got the crowd going wild with a duet performance at a modest Hongdae cafe in Seoul's Mapo District.�

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The two artists declared that they have always been fans of each other on social media, making it no secret that they would very much like to perform together. After appearing side by side on 'Infinity Challenge,' the IU and hyukoh crossed paths once again during hyukoh's concert in Hongdae.�

Without prior notice, IU stepped on stage to join the band, much to the delight of the audience. And delight she did as the singer performed an acoustic rendition of Lee Moon Se's "Old Love" and lent her vocals to "Gondry."�