They should rename this movie "Missed Opportunity".

Not gonna lie, I am quite disappointed, especially after reading the synopsis. I was ready for some complex story that pushes the viewer into a state of constant questioning of what is real and what's just a part of the broken imagination of the female lead... Well, I did not get that. If they just kept it a bit more vague and made sure Mi Ju is actually present during all the "supernatural" occurrences, it would be so much better. But since a lot of crazy things happened even without her being near, the answer is given to the viewer. When trying to create a story that can be left to the interpretation of the viewers, you need to be careful as you craft it. They were not.

One of the biggest flaws of "Cello" was the acting. I don't know how much of it I can blame on the actual acting skills (or lack of them) and how much blame can be put on the "acting style" that might have been more popular in 2000'. Either way, it was not good. The line delivery felt awkward in a lot of scenes and it took me out of any suspense they tried to create.

The plot was just a clusterf***. For such a short movie, they introduced too many characters we were supposed to care about. Why add the husband's sister? Or the "blackmailing" student? None of the plot lines were necessary and only took the precious minutes from the main character and the development of whatever supernaturally or mentally was happening to her.

Overall, I would probably not recommend it. There was nothing exciting, innovative or interesting in this movie. If anything, it left me frustrated, because the concept was good, but the execution of it just failed.