Boy band KickFlip returned Monday with its fourth EP, “My First Kick,” leaning further into the bright, unruly energy the group has been building since its debut into a bolder collective statement. At a showcase in eastern Seoul, KickFlip introduced the seven-track album as a release built around “firsts,” from entering their 20s to taking on new musical and performance challenges. The album is led by the lead track “Eye-Poppin'," a hyper-punk dance song that channels an aggressive, cheeky kind