I was lucky enough to have binge watch this, instead of waiting for so long waiting to get the happy ending we didn't get in season 1.
This drama is definitely not for someone looking for a happy ending you expected, but there is a happy ending.
Just like in real life, you fall in love and for one reason or another you break up, and later in life fall in love again. You don't always end up with your childhood or highschool sweet heart. You may not even end up with someone you fall head over heels for. You may end up like JoJo (and Sun Oh too), finding someone that love you and support you unconditionally and you learn to love and appreciate them eventually. Criticize all you want, but love is not always about a happy ending you want, sometime it's a happy ending you need. And learn to be happy with your choice in life.
For me, Jojo learned to really love Hye Yeong proven by her effort to remove the shield, to give him the assurance he needed through the app. That's one thing I dislike from this whole theme, how people put their trust on technology to find out if someone truly love you.