K-pop girl group UNCHILD returned Thursday as “bug busters,” unveiling its second digital single, “TiNG TiNG,” with a playful mission to take on digital glitches. During a media showcase at NOL Theater Hapjeong in Seoul, five members — Yeeun, Tina, Ako, Evon, Haeun — introduced a release that turns their unconventional identity into a colorful superhero adventure. Taking a playful cue from “Ghostbusters,” the concept casts the members as offbeat heroes pairing house music with playful characters and choreography incorporating locking. “If our debut showcase was about introducing UNCHILD, this is about showing a new side of ourselves, so we feel nervous,” Yeeun said. The six-member group debuted in April under High Up Entertainment, becoming the agency’s first new girl group since STAYC. Its name draws on the prefix “un-,” expressing a refusal to fit established norms. That spirit initially took shape through neon colors, reworked school uniforms and a green frog symbol — a nod to the Korean folktale of the frog that does the opposite of whatever it is told and