"Different"

Yo han always had difficulties expressing his emotions. Maybe that's why he never cried. Yet for the first time in his life, he felt a large amount of water come out of his eyes and run down his cheeks. He was overcome with emotions he couldn't explain after hearing him sing.
Since that day, Yo-han has continued to feel many emotions that he couldn't define, some more stifling than others.
By bringing Ga-on closer, what other unknown emotions could he feel?