What to say about this ending? They romanticized a toxic and abusive relationship. They romanticized that a woman is indeed a repair shop for men. I feel shame and pity for Na-bi because in that conversation where they return their relationship, it is evident how emotionally dependent she is on him. She knew what he was like, what he put her through, and yet she threw herself into his arms again. I am disappointed! Fortunately the secondary couples - Sol and Jiwan, Bit-Na and Kyuhyun, Min Young and Kyung Jun - saved that story.
They could have made Na-bi discover female empowerment. They could have made her realize with Jae-eon that no one deserves to go through an abusive relationship. What about Jae-eon saying he fell in love with her at first sight? This was never a crush because if he really had fallen in love with her, he would have had intentions of getting into a serious relationship with her from the start. And not just after losing her. What starts wrong will never work. Except in Nevertheless, history made people think everything that happened was normal.