Hakyeon's just a wallflower, especially after his sister recklessly drove the two over a cliff leaving Hakyeon disabled without the sense of hearing. Silence. It could've driven him insane at one point and he's ready to give up. When a new volunteer named 'Leo' enters the hospital, Hakyeon is determined to hear his voice and the melodic notes he'd play on the piano for Hakyeon each day.