I really liked this one and I feel like it healed the need that I had to see Bae Suzy as an idol again. It was all well done but I wish it had been a bit longer. All the actors were so amazing and their chemistry looked so real and overall everyone gave off a good vibe.
I don't think it had a sad ending, in my opinion they didn't part ways completely, they still think about each other. Even if no one else knows what they shared, they'll know and that is enough to last a lifetime.
Anyways I hope whoever watches Doona! will enjoy it as much as I did.