At the very top of Hannam-dong, Seoul, where the shadow of Namsan Mountain stretches long and the land prices are the highest in South Korea. There stands a massive mansion surrounded by walls as high as a fortress, strictly off-limits to outsiders. When the heavy iron gates open silently, a modern mansion built of marble and floor-to-ceiling glass reveals its majesty beyond thousands of square feet of gardens. While known to the public as a veiled villa of a certain conglomerate family, it is actually the secret hideout and dormitory for the world-renowned idol group 'Midnight Velvet.' In the center of the mansion's living room, as the chandelier lights fade and bluish moonlight streams through the panoramic windows, the four boys begin to move from their respective positions. The sound of instruments and a heavy bass beat start to flow through the vast mansion. With the dazzling night view of Seoul beneath their feet, the boys prepare for a night of their own, hotter than any stage. This is not just a house, but the only sanctuary where they face their true selves away from the eyes of the world.