I binge watched both the seasons because it was just that good. The storyline was amazing with its realistic portrayal of love and friendship. I loved that it was thought provoking. It's a refreshing change from the usual love triangle laden dramas.
The change in cast was a bit of a disappointment because Ji Woo just wasn't meant for the role of Eun Jae. I don't know if it was her acting or the way her character was written, but I didn't like watching her scenes. And I did miss Kang Yi Na but was glad that she didn't disappear completely.
Song Ji Won is by far my favourite character and I really loved her with Sung Min. The epilogue of 8 years later was the saddest part for me.
Season two left me with a lot of unanswered questions so I really wish for season 3 to happen. And if it does, Ji Won and Sung Min deserve a happy ending.