The main problem of the Korean Drama " Cinderella's sister " is the characters. Most of them are annoying and the progress of the story finds them with close to zero character development.

One of the worst is the sister, the 'cinderella', who cries ALL THE TIME! At first, it's unnoticeable and blends in with the rest of the drama. However, especially after the second half, her crying increases and she gets worse and worse. Not to mention that she acts out of character in the final episodes when she discovers something that she didn't know about her family.

The male lead is also one for the books. He not only plays with the two sisters' feelings, acts selfishly and does the most unreasonable things, but also his reasons for doing what he does are not that great, in the end, and do not justify his actions. His romance, thus, with the leading lady was problematic and, most of the time, frustrating.

The rest of them are either annoying or just okay, except for the father, who was probably the only one who was likable. The sister and leading lady was, after her teenage years when she was simply impossible, pretty decent and she was one of the few who acted rationally at times.

As for the story, it's okay, melodramatic and depressing, but with a good family drama. Though, most of it was predictable. In addition, there were episodes that were boring and dragging.

Finally, the soundtrack was really good and the performances great, especially from the leading lady.

So, overall, three out of ten.