What can I say about this drama, oh yea, it had me at hello. I loved it. Reliving my university days is fun. So many lovely memories about entering in the easy classes, we have all been there.
The main characters Yoo Sung and Hong  Seol  had me captured in a sinister web, I believed her that he was pure evil, my heart was racing everytime Yoo Sung came on screen, waiting, wanting, needing him to be as Hong Seol depicts. A stalker for sure, to the point of being a bit creepy, but we will had to wait to see if he turns out to be a good guy or bad. 

The title Cheese in a mouse trap, so fitting, her hair color resembles cheese and Yoo Sung reference to eating, wow! Yoo Sung is liken to a mouse chasing the cheese Hong Seol in this episode. It was fun to watch, I keep wondering where he would pop up next.

Side note, lots of eye candy, like Seo Kang joon and Nam Joo Hyuk
I didn't really get the title until I read your post. It makes total sense, now  I get why Yoo Jung has sociopathic tendencies. Actually, I think he is a sociopath.
Do you imagine he is the bad and song heol doesn't end up with him but baek in ho.... that would be an interesting twist... Maybe yoo sung is miserable and needs a someone that doesn't want to be with him for money, because he's the one always paying for stuff... Anyways, how handsome are the guys in the drama?  Very handsome... Can't wait for episode 5... What do you guys think will happen....
I'm really hoping tht hong seol ends up with baek in ho.. I'll be extremely disappointed if it goes the other way around. I was thinking the same thing about Yoo Jung, but it would be sooo interesting if he really is a sociopath.. this drama is just so much fun to watch. Next ep idk what will happen, hopefully something to Yoo Jung and Hong Seol will break up?
Am hoping for more sinister action from Yoo Sung, he can manipulate people to do the dirty work, like when he use the school guys to beat up In Ho or when he presents the receipt to the nerdy guy to take revenge on the guy who was stealing the group funds. He had a dark side for sure, just how dark, we shall have to wait and see how it unfolds.
I also hope to see more of the love triangle, who will fall first
Wait, so Yoo Jung was the one who got In Ho beat up????!!! I didn't know that! It's believable, but wow, this guy is scary manipulative. The reason why I'm more inclined to believe he's really a sociopath is because he set up tht whole thing with the receipts. He is definitely shady, thts why you should always trust your gut instincts. Something told Seol that there was something off about Yoo Jung, and I think she's right. 
I mean that's what I also understood that it was yoo soung behind the in ho's incident... well, let see how the writers decide to do the series becaue they've caught up to the webtoon... is the the author of the cartoon helping in any way to the script? or is it another diferent spin?
Oh, I have no idea. I've never read the webtoon. So I guess the webtoon isn't finished yet? Wow, it must be super popular for them to make a drama out of it when it's not even done yet!
This drama could take the darkest, most unexpected twists but I don't think that'll happen lol. If this series was japanese, it'd be more than possible. But korean nah
It'd be really awesome if it did tho..
@JPT just to set things straight - they're no-where near catching up to the webtoon yet. The webtoon's English version.. maybe, yes (there's more to cover actually from season 2 than it has yet). But there's a lot more out in Korean (currently on season 4).Yoo Jung is more complicated than just plain good or bad or shady ;) And we haven't seen most of Hong Seol yet.. 
I really hope they won't make this more about the love triangle than it is in the webtoon and stay on the course they are. A girl can dream..
In episode 5 i can sought of see YJ logic the assistant stole so why not use it to help the girl who caught his eye also he may not have anticipated how the students would treat the assistant after woulds.The assistant shouldn't be angry really he could have reported him to the school and police and that would be the end of his job and career plus he said he needed money but the owner of the wallet might have needed it for something even more important.Although i still hope YJ gains some feelings soon.
@riinirmeanie - yeah, the English version... although there are several things they jumped.... I don't in other languages or Korean so....
@JPT yeah. I understand. I hope you didn't take it the wrong way. I see a lot of comments how it has caught up with the webtoon and it's not quite right :D just saying. They have jumped a couple of things and kind of fused some scenes into one and used some other characters in situations that drive the plot but originally had some other character in it. I think they're doing a great job adapting it and it's fun to see how they've done that.