Overall, this show is pure PERFECTION! Park Seo Joon and Park Min Young are fantastic actors.
Their chemistry is off the charts and you can't help but love their characters, rooting for them and finding them incredibly funny. Yes, because this show will make you laugh out loud (this show is funny in a way that reminded me a bit Marriage, Not Dating), in spite of the dramatic experience the lead characters shared as children. It's very well written (comedy and drama are perfectly balanced, and there are no filler episodes) and extremely well acted, even by the children actors (seriously, how good are those little kids???)
I also need to reserve a very special mention to the supporting cast. I confess that, on many shows, I skipped the scenes with the secondary characters because most of the time they were not interesting enough and were basically "sucking" the screen time of the main leads. This is NOT what happens here. ALL the secondary characters, ALL of them, are so well written that even their storylines are engaging. They're three dimensional, not just there as fillers. Kudos to all the actors and characters (particularly the adorable President Park and his amazing bromance with Lee Yeong Joon).
Finally, this k-drama has the most beautiful kisses/love scenes I've ever seen in a Korean show, yay!!!
It's officially one of my favourite shows ever that I need to watch all over again! 100% recommended!