In February 2008, the Wonder Girls joined their producer Park Jin-young for his month-long concert tour through Korea and the United States as special guests, where they filmed the music video for "Wishing on a Star" while in New York. "So Hot" was released on May 22, 2008. The song topped online charts soon after. In mid-2008, they performed on MBC's "Show! Music Core", performing "So Hot" and "This Time". Due to a vocal cord injury, Yubin temporarily lip-synced her parts under doctor's orders.