You need to have the right mindset to read this.
Let's imagine something. Think of a teenage boy in high school. He's your friend. That boy, you see, is very sensitive. He cries easily. He's also weak, bad at sport, clumsy and looks a bit a like a girl. Almost every time you go out with him to do something, he will either stumble and fall, or drop something, end up hurting either him, or you, or someone else, and break something something you own, drop water or any other thing on you. He's so much indecisive that he ends in an hospital because he doesn't know what he wants to do, so he bleeds from his nose and faints (and I wish I was joking here). So, that boy, you see, is our protagonist here, Yeonwoo.
He's not a bad kid. He's sweet and kind, but also very shy, and maybe a big coward too. The thing is, if he were my friend, I wouldn't be able to bear it. I'd end up tired of being with him because of how extremely sensitive and clumsy he is.
The female main lead on the other hand is his exact opposite. In my mind, I call her "Robot Girl". She's kind of a kuudere. The author probably tried to create a cool and cold character, but most of time kuuderes are cute. And she's not. She's supposed to be extremely beautiful, the equivalent of a model, but I have to admit I can't see it. She isn't ugly, but I can't really call her beautiful either. If you have ever read a romance aimed at girl, then you can probably picture in your head a guy with black hair, tall, taciturn, good at everything, and always ready to protect the female MC. That's our FML here, Haseol.
In fact, this feels like a romance written by a female author aimed at guys, but here the roles of the main characters are reversed.
The problem with this manhwa is the impossibility for me to believe and accept its premise. The MC is so extremely sensitive that it's literally impossible for me to read one chapter without having to make a pause while thinking "You dumbass!". Is there any guy like him in the real world? I don't know, maybe. I've never encountered someone like him in all my years though. And like I said, if someone like him was my friend, I don't know if I would be able to bear it. And I was a crybaby until middle school. Still a coward though. But even for me, he's too much.
I could say it is a rather OK manhwa, with some interesting side characters (in fact, the side characters are more interesting than the main ones), the drawing are good. But boy is it a drag to read. The story could have been a bittersweet slice of life about a very sensitive boy, with some funny/sad side characters and a bit a humor/sweet moments, but instead, almost every chapter, there is some forced drama, the MC will make an error, be embarrassed and/or depressed about it and run away.
So, be warned. It is a very, very, veeeeeeeeeeeeeeeeeeeeeeeeeery hard to read manhwa while retaining your calm.