I'll be completely honest. I watched this drama because of Jaeyoon. I found this on his feed and I was like I have to watch it. To be honest, I didn't really like it much. Though the concept is not something you would find in a drama, I didn't liked it. I felt that concept of white hole and black hole is not a topic that I or anyone would find in any drama, either western or korean. Overall, in my opinion, it is a one time watch if you like to discover new concepts. If you are a fantasy, (SF9'S fandom name, incase you didn't know) you have to watch it once. It is a new concept. Worth a Watch.