The drama starts of from Na-bi freeing herself from a toxic relationship but little does she know that soon she will enter the same path with Jae-on. Ofcourse we all would've felt butterflies seeing the chemistry between the two main characters when they meet at the start however we also knew what kind of person jae-on was so we wished for him to have a character development. I would say that we didn't really get to see his development fully as he only starts to change in the last episode. This is presented when he finally releases his butterflies after episodes of saying that he will. Butterflies were used as a metaphor of rebirth and change and releasing them meant he is ready to let go of his previous "flings" and his actions such as flirting. Whether he really changes or not is for Na-bi to handle because what went through that girl's head. At the end I would've just wanted her to stay single because Do-hyuk did not deserve her. Jae on literally is such a manipulator I will never forget the way he harshly grabbed Na-bi's hand in the second last episode. Even after having a go at him she still ended up going back to him. The side couples definitely carried the show for me it was so sweet watching them. Overall I think the ending was a big disappointment and the ending of the webtoon was way better. Also Sam Kim's OST was just perfection the butterflies it gave in the first half.