A short disclaimer. I watched this drama about half a year ago, so I do not remember everything that quite well any more.
What I do recall nonetheless is that I totally loved it and that it was addictive to watch.

The drama is about Yoon Ji Ho who lives a miserable life. She is a drama-writer and gets used by her boss. She is not allowed to write what she really likes and gets sexually assaulted by her colleagues. Furthermore, her little brother got his girlfriend pregnant, and her parents kick her out of the house, she paid all the bills for. She quickly needs to find a place to stay and rents a room online. Because of her name the owner of the house is not aware that she is a woman and due to their daily schedules they do not see each other for a couple of days. However, when they find out that they are living together with the opposite sex, they are drafting a contract to get married. Nam Se Hee an (Owner?) of a dating-app company needs a wife to receive money from his father, and that is why the marriage comes handily for him, too.
Next to the main characters, we meet their best friends and love interests. Yang Ho Rang's goal is to get married to her boyfriend and have a family. Her boyfriend Shim Won Seok also works at the same company as Nam Se Hee and is unsure about what he desires. Yoon Ji Ho's other friend Woo Soo Ji works in a huge company, in which women are treated awfully, she needs to fight her way to the top.

So, what was so special?
What I absolutely enjoyed is that the drama felt very realistic, and the characters stayed true to themselves. Yoon Ji Ho is rather a silent girl. She is not good at standing up for herself and she gets an amazing character development, but she is never portrayed like not herself. This accounts also to the other characters (but with different traits, though).
Also, the drama talks about couples living together, having sex and many girls talk.
I would compare it to a very good mix of the general Korean standards of a drama but with rather western features, if that makes sense.
Yoon Ji Ho and her girls squad are hilarious, and I enjoyed their interactions. They very much reminded me of my two girls. Also, one in a long term relationship and the other making carrier and me being somewhere in-between and nowhere:D.
Every story was nicely built, and all the relationships developed differently. There were also a lot of twists and turns.

So do not hesitate any more and give it a go. :)