This drama can go in two ways. Some people feel disgusted by the plot and others feel warm and fuzzy inside after watching. This may have only been me, but I was in between the whole time.

Beginning ep 1-6:
When I started this drama was a perfect cliche, but I happen to love cliches so it worked out well; the wealthy businessman, the illness and the marriage contract where they fall in love. It was cute and I liked it, the main cast had so much chemistry and I loved the side characters too.

Middle ep 7-14:
This is where things start. First, we have another cliche *spoiler* car crash and then amnesia. Pretty basic though and I wasn't worried. Episode 10 and 11 are where people choose their sides. A crazy plot twist turns a majority of people against the main male lead. and i agree:
He's possessive, creepy and overall seems to be toxic, but the show almost portrays it as true wonderful love at first sight. It's not. Don't recommend if you can sense these details even with a cover-up as love. But I kept watching.
*spoiler**spoiler*
they get back together, i know so unexpected
after that things happen but it's still very cliche and kidnapping and trickery, all that fun stuff

Ending 15-20:
I didn't really concentrate on it because I was disturbed, but there were some cute moments that made me doubt my disgust. Surprise! A child is born and it's a happy ending (or so we're told)

Honest opinion:
Many people say this is a cute, heartwarming show and they recommend it. I understand because I thought so myself but after the twist, I was unable to rethink anything. The beginning is very misleading to their relationship and I personally would not recommend it to the soft-hearted or anybody suffering from a toxic relationship. Overall the acting was wonderful as it fully disgusted me and made me feel horrible for the female lead, the music was not super memorable, but after watching, I would never be able to watch it again, especially given that I usually don't rewatch any shows except the forgettable web dramas