I felt disappointed with this drama. The story line was interesting but the constant back and forth with no real solution. They kept talking about punishment for using time but who was going to punish him. Time is science and there is no punishment. As a scientist he never really care about finding a solution to time changes. Plus how can he not know the past when he was in the future. To me does decisions where already made. If he went back and change the past his future changes but is he is in the future how can a decision from the past change the future when he did not change that moment in the past. I am gathering that the writer was also talking about destiny. If he was destine to meet her and fall in love nothing he did can change that. If you believe in destiny. The chemistry in this drama was great and the actors did a great job in their performance. I found it confusing and to many repetition on some of the episodes it got me board. The couples also took so long to get together in the past and the future. I will let you make up your own mind.