SHIN JIMIN, formerly the leader of K-pop girl group AOA, is a veteran of her industry: She debuted with her band back in 2012, left following a bullying controversy in 2020, and, in 2023, dropped this highly anticipated debut solo EP. It’s a complete transformation from her first solo release, the explosive hip-hop-pop of 2015’s “God,” which featured N.Flying leader Lee Seung-hyub. BOXES’ ambitions lie in rock ’n’ roll, from the ’90s dream pop “Somewhere” to the Verve-esque Britpop “Sympathy.” The back half recalls early-2000s emo rock on “Don’t know why” and the pop-punk closer “Suddenly,” complete with nasal performance.