I just finished watching the K-drama and let's start with the positives! Well, as you can see, it's a very simple drama aimed at being cute, and in my opinion, it did a good job in that aspect. I can't even count how many times I felt like a lonely single woman watching the romantic scenes ??.
I also laughed a lot at the funny scenes, I found it quite entertaining. Oh, I liked the theater! It was very cute. The actors' performances were also great in my opinion, and finally, the story is quite interesting.
However, let's move on to the negatives now.

1st When the history teacher reunited with his beloved in the present, she was a teenager and in the past (apparently) she was an adult, so I found their reunion strange... I think she should have come back as an adult or not come back, you know? It left a kind of... weird atmosphere.
2nd The CGI of "Cocoa" was bad ? it was noticeable when they switched the real dog for CGI.
3rd The part of the story where the math teacher's rival in adolescence appears was unnecessary. He and his henchman made no difference to me when the real villain already existed.
4th The "romance" of the protagonist's uncle with the teacher was... strange and forced. Besides, the uncle had already died when he was in his dog form, why did he come back to life the next day?
5th There were many repeated scenes (the so-called memories blah blah) they were boring .

Well, there were other things I didn't like much, but overall, I had fun moments watching the drama! It was great to see 2 actors (Cha Eun Woo and Park Gyu Young) that I like acting together, as well as meeting a new actor that interested me (Lee Hyun Woo).