Short: Fun, cute, many funny moments as the cat learns to be a person and still exhibits cat-like traits (finding a box to sit in...). I enjoyed it a lot until the ending which was clearly just abruptly cut short and frankly made no sense. Apparently this is another one that was cut from 16 to 12, but in this case they just lost 4 episodes of story from the looks of it. It *does* end, but a bit like "Abyss" it's unexplained. By the time you finish this, you'll firmly know the Korean for "cat" :-)

Detail:
Really good to see Shin Ye Eun in another drama as a lead, she was great in He is Psychometric too. Also thought Yoon Ye Joo did a great job in her role as the shy Ji-Eun - frankly all the actors were great but those two stood out for me. The cat was fantastic too, helped along some times by a Computer Graphics render of a cat where they needed particular things and couldn't get the cat to cooperate, but most of the time it's a real cat.

Basic premise is a cat finds he can turn into a human when around his owner Sol-ah, humorous things happen when she mistakes him for the step brother she hasn't met yet. She's a webtoon author and finds herself inspired initially by the story of her and someone from her past who just stopped talking to her, that she represents in the webtoon as a cat - and then starts evolving the story based on Hong-jo's thoughts (while he's pretending to be her step brother) and the story takes on a new life. In many respects it mimics the events happening in the drama.

It's fundamentally a fairly simple plot really, some nice bits where he helps some captured cats out as he's captured himself, and talks to other cats who can turn into humans too.

I've seen commenters (not sure if on here but certainly elsewhere) expressing negatively about the idea of a person and cat in a relationship but... its a person, there's worse out there in drama land, just chill. :)

But the fundamental problem with this is that they set down some rules eventually for the changing from cat to person, and ultimately break them without explanation to give the ending. My gut feeling is that given this was shortened from 32 to 24 episodes - that the missing 4 hours are the journey from where they end up in episode 24, to where they end up in the last 10 seconds of episode 24 :) I think 24 episodes ultimately would probably have been enough, in retrospect there was a bit too much meandering, too much time spent where she doesn't know that he's the cat, and probably if anywhere that's where i'd re-balance things.

Still - it IS still worth the watch, it's good fun with some funny moments and the music is entertaining too.