An inside look at the K-pop phenomenon, in a wry, punchy young-adult debut that probes cultural differences, sisterhood, and the minefield of fame. Every Friday after school, dressed in their new South Korean prep-school uniforms — sweater vests, knee-highs, pleated skirts, and blazers — seventeen-year old Alice Choy and her little sister, Olivia, head to Myeongdong, brave a dank, basement-level stairwell full of graffiti, and slip into a noreabang. Back in San Francisco, when she still had friends and earthly possessions, Alice took regular singing lessons. But since their diplomat mom moved them to Seoul, she pours herself into karaoke,…