Hyeon-joon, who transferred to Gwangsanggo, meets Jin-won, Byeong-yeon, and Yeong-soo, who are armed with a knuckle, and forms to be the fourth musketeer. As the Four Musketeers continued their fearless moves, the rest of them showed up one by one. Face it! The unprecedented and ignorant youth...
Because of grandfather's will, Ju Won somehow feel uncomfortable about this flight. He accidentally reunite with a manager of J- one, Gu Reum. After they finished their flight, something shocking happens to Ju Won and Gu Reum.