Sejin perceives the sounds of the world through a cochlear implant that converts sound into electrical signals. From a 2-channel hearing aid where people's voices sounded like footsteps, to a 48-channel cochlear implant, the technology that enables hearing has advanced over time. However, with each cochlear implant mapping, Sejin feels even the voices of those closest to her differently. "I'm tired of being real, I guess. How long can I be closest to the 'real sound'?" Ju-hyun was curious about the sounds Sejin perceives, but soon, her curiosity shifted from the sounds Sejin hears to questioning the direction of technological advancement for cochlear implants, which are equipped with technology to make speech audible (and thus have the user's purpose of integrating into a hearing-centric society).