I love the plot and the OST. The FL is my favorite as well as her parent, they are really supportive & loving. The ML is indeed a psycho, but imo his worst era is when they were in Uni, we can see from his hair it's a symbol of drifting away from the "right path". Nevertheless, he is very protective of the FL and loves her quietly. There is some symbolism that we can pay attention to. Some people said that the ML is taking too long to confess his true feelings, he is, but I think it's natural for him to do so. It's such a beautiful drama honestly, I am 100% sure you will instantly remember your first love while watching this!