Seung-jin, who is preparing for an audition to pursue his ambition of becoming a singer, moves into a new studio apartment. On the first night, as he just started to settle in, he hears a woman wailing from next door. With all the noise she makes owing to her badly soundproofed room, La-ni has driven away several neighbors. Seung-jin isn't one to back down easily. Their argument intensifies to the point that they have discovered everything about one other's life through their noises save for their names and faces.

Ji-hoon longs to see his college love Ye-eun again, but her marriage to violent Hyung-oh has drained her vibrance. To save her, Ji-hoon hides under their bed.