Wow, this was a rollercoaster for me. When I heard about this drama, I was immediately interested, although sci-fi and technological things aren't really my thing. After the first 3 episodes, I was slightly disappointed. The story was kind of boring but I still wanted to watch it because the main lead was so impressive, acting as two different characters. The female lead was good but I wasn't sold yet because her character was hard to like at first (her choices were a bit dumb). I also couldn't understand how an AI could be so loved. After episode 7, things completely changed for me. I was hooked! The last two episodes specifically were amazing! Usually I find the first episodes better than the last but this drama was different: it kept getting better and better. The plot, the action scenes, the pace, the acting! Everyone is such a good actor in this! Plus, all the frustrating things about this drama disappeared as the episodes went by and as things started getting explained (and as we got to know the characters). I cried multiple times watching the last few episodes. All I can say is, if you decide to watch this show and don't find it that interesting please stick with it until episode 7 or 8. I was planning on giving this 8.5 stars but now I'm giving it 9.5 stars! The last four episodes were THAT powerful hahaha. It's very beautiful. That ending scene... the tears kept coming.
It's definitely worth your time so please give it a chance!