okok so basically I feel like eunjae is the ML and the reason why they both returned to the past is because they both had things that they regretted about their past selves so this is a chance to change the mistakes that they've reflected on. In Hayoung's case I feel like she was taken back into the past so that she wouldn't regret having not confessed her feelings to jaehyun before and through this she learns more about jaehyun as a PERSON rather than the picture perfect image that she had of him originally. This is only my guess about it so can anybody correct me if I'm wrong?
when I saw Daniel I was like "there's no way that I waited for 40 chapters just to see an average looking dude like that." BUT PLEASE HE LOOKS SO FINE IN CHAPTER 42 ZKFNKJDNJFKNFDJNDJDNKJDFNDJFNJKFFDVCMKMFSD