What do you guys think about Seo Kang Joon and Gong Seung Yeons chemistry on screen? I've heard from some people that they hate them together because all of the romantic gestures and lines between the two seems too rehearsed and fake. Other people say that they fit perfectly  together and that their chemistry is amazing. So what do you guys think? 

I don't have any issues with the chemistry. I think they are perfectly fine. Without spoiling there are some scenes where Kang Joon is staring at Seung Yeon and you can really feel the chemistry. Gosh it even feels like his glaring right through my soul. Those who say there isn't most likely because they don't like either the actress or the character. From some reviews I've come across I just laugh because they must be watching a completely different drama to me. 

They have good chemistry in my view. So far we haven't seen many romantic moments, but their comedic scenes are gold, and in order to be funny together, you need good chemistry I think. I'm shipping the couple robot-cyborg, so of course for me they work together. I think that the ones who don't like it, it's because they don't like the actors or the story, and this way it is difficult to enjoy anything else.

They have good chemistry. I like how they're more like buddies and pals, that makes their interactions more down-to-earth and relaxing to watch. For me, a good couple is when two people can truly be themselves and be able to laugh with, have fun with, and comfort each other. The joking around, sarcastic remarks, and body contact show that they are really comfortable around each other like lifelong friends.

Anyone who denies the chemistry these two have must be insane,  all of their scenes have me smiling like an idiot and it's between a robot and a human, which the two actors are doing a good job portraying btw. 

Their chemistry is so good like what are those people smoking? 

lol they prolly meant the chemistry between gong seung yeon and human nam shin is fake/nonexistant ? 

While I surprisingly love this drama, it's not their "chemistry" that is a problem, they're fun together, rather it's the fact that the male lead's acting skills outshines the female lead's. Seo Kang Joon is so much more impressive (I think he emotes better). It's unfortunate but maybe it's the way her role was written too. Nevertheless both are talented and I am pleasantly surprised by this drama.

I so wish this scene of Inhuman-Shin carrying KbS into the Vip hospital room made the episode!

https://www.youtube.com/watch?v=ttzhVom1OQM&t=9s