Luhan left his rebellious days behind. Now he keeps to himself and tries to avoid any situation that requires him to leave his comfort zone, to the point where his best friends brand him a 'social recluse'. 

Song Jieun has been deaf and mute since young and despite her hearing disability, she tries to not let it hinder her from living a normal life. She has a decent job, she enjoys spending time with her friends and more than anything, she likes to explore.

When they cross paths, a relationship blossoms between the two and with their seemingly contrasting personalities, they help each other overcome their weaknesses; his fear of sight and her fear of sound. 

Don't you miss listening to what is around you? Music, laughter, your own voice? Don't you want to hear? - L

And you, don't you want to look for what awaits for you out there? Don't you want to see how beautiful the world is? - J