Fifteen boys dreaming of being the "future of K-culture" enroll in a "school" to find the answer to a successful debut! A time-slip curriculum designed to win the hearts of fans across every generation, built for future-forward stars! [ To see the future of K-culture, you have to know its past?! ] The 90s saw the birth of Hallyu. The 2000s marked a golden age that dominated pop culture. The 2010s sparked the global explosion where the world fell in love with Korean stars. This is not just an experience, but real classes that teach the unique vibes and emotions of each era! Once the lessons are over, it's time for the real deal! Eating together, sleeping together, and diving headfirst into preparing a festival performance! It's a 24-hour close-up reality life with no eliminations and no going home! A time-slip growth variety show, <Reply High School>.