This is one of the 'feel good' type Kdrama..It's got a great storyline, timely comic reliefs.. it's about sci-fi, being human, time, memories, courage and trust. The seriousness and dark mode never lasted too long and it faded away with the best climax I have watched.

The main characters are just hilarious😁😁😁.... Yoo Seung-ho is indeed a great actor. His acting is flawless...
Each and every actor and their characters are awesome as they are done justice on till the end.

The ending of the story is beautifully and leisurely written which just warms your heart. If you are feeling sad after watching a sad story you should watch this for heal yourself. I love this wonderful drama with a happy ending...