If abuse explained as love, with overwhelming unexplainable love for the abuser might bother you, this is a definite skip. If you can ignore illogical plot devices, abuse, and poor character development and only focus on the cute fluffy romance between the leads then this is an ok filler show.
Can't complain about the actors, they all did well in their roles. The screemwriters themselves killed the story. As others stated, there is no character development, backstories are a shallow, and plot/motives are lacking in depth and logic. This kind of sloppy writing makes it seem as if horrible parenting is the cultural norms. The grandfather exists in the story only to abuse his daughter and grandson. He is brought out only to ruin their happiness and worsen ML's problem. And yet, because of filial piety the mother ignores his behavior and pressures her son to accept the abuse as family love, which he does. Not acceptable! Filial piety is not a crutch to beat your family with. It's not honorable or noble to overlook abuse because it comes from a family member. If the mother was truely filial to her son and father, she'd have told her father his behavior is unacceptable and he has no place in their lives unless he changes!! Horrible parenting and insane love rivals are the most lazy and irritating plot devices in c and k dramas.
Thankfully they stopped the stupid male love rival fairly early and did not bring in a crazy female rival.

The explanation of his illness was ridiculous!! The writers glossed over the abuse by saying it was because he loved his grandson so much he couldn't help but call him "filthy, worthless garbage" when he wasn't ignoring him. ML developed mysophobia because the person he loved most kept calling him garbage. ? That is complete nonsense. Gpa isn't a bad guy for not clarifying the accident and letting them break up, because it was for the company . His driver did cause the accident, he made his driver turn himself in and gave the wife and kud money to help them out. In what way could this possibly hurt a company? Of course this was forgotten once the truth was out and the leads got back together. All is forgiven with gpa cause he said a few nice-ish things at the end when prompted by the mom, and gave him a box of old things he bought but never gave. More sloppy nonsense!!