Girl group Lightsum is rolling out a digital single from its first subunit on Thursday, according to Cube Entertainment. Sangah, Chowon and Juhyeon have formed a trio and unveiled their retake on BTOB’s 2018 single “Beautiful Pain.” They shared their thoughts on the endeavor via the agency. "We are truly happy to be the first subunit and are excited to be able to show our different sides," said Chowon. Juhyeon added that the three have performed together often since their trainee days, and the s