The story, cast , music everything was perfect until last episode, the ending felt too rushed, that many important points that connect past to present were missed.
I wanted to know how Eun gyeol life changed in terms of wealth and family relations, did Yi Chan and Chung Ah meet again in US, what about the story that was present before Eun Gyeol time travelled and they didn't show anything about Eun Yu's & Se Gyeong story. I think a special episode where all the missed story should be aired to answer most of my questions.
Overall the drama was pretty good. Had many emotional scenes that had me in tears, osts are also pretty good. Do give it a watch. The idols have also acted well memorising the sign language.