Blackpink and Twice, two of South Korea’s most prominent K-pop female acts, made high-profile returns on Friday with new releases, heightening expectations for a rebound at their respective labels, YG Entertainment Inc. and JYP Entertainment Corp. At 1 pm Seoul time (4 am GMT), Blackpink fully unveiled its single, “Jump,” a fast-paced electro dance track that debuted live last Saturday during the group’s Deadline world tour kickoff.