Some people use to have some kind of prejudice about this series, just because the main characters of this manga are 3 little girls, and because of the name, which is actually very catchy, but doesn't tell you anthing about the series when you translate it. I myself was actually a little bit skeptical to ZKC at the begining, and not due to prejudice; however it only took 2 chapters for me to get interested on it and maybe 4 or 5 chapters to be completly hooked by it. The story is narrated in such a beatiful way, and the characters are so well presented that you can't help but to empathize with them in just a few chapters.

Story.

The story is one of the strongest points for this manga; it tries to show, in essence, people who is different from the rest, how society takes these differences and, in contrast, how does this affect the personality of this different people as a result of society's reactions. Topics like: Racism, self integration, friendship, revenge, hatred, prejudice, tolerance, and a lot more are included is these manga's plot. The story shows different sides of a common problem; while some characters develop a personality full of hatred and resentment towards the ones who discriminate them, others try to overcome the prejudice they're vistims from, and the hardships that this carries, with the help of the people around them.
The antagonist lets us see the mistakes made on the past, and the protagonists show us the effort they make in the present to overcome a dark future.

Art.

The art starts being a little bit plain in the first chapters, but it improves very fast as the chapters keep going. It is easy to notice how the author starts to feel more and more comfortable with his characters and tries new things and new styles.
The design of the characters is very good and goes perfect with their personalities, which helps you to empathize with them more easily. The design of the scenes and the order in the pages is also good and is a great help to get involved with the situation and the events you're reading, and with the whole story.
The desing in general suits perfect for the content of drama and sometimes comedy that this series has; it can be easily appreciated in the cover page of each chapter.

Characters.

The chracters are also a good point. We have "the children", the 3 little girls that protagonize this series; they're absolutely lovely, as the name suggest. You'll need just a few chapters to get hooked by their charms; this three girls have a lot of charisma and their different personalities make a good combination which will give you a lot of escenes of laugh and drama. Their personalities have a wonderful development and show a real growth; they grow magnificently along the series in both age and personality. The other characters also show a great growth, but mainly two of them:
-The guardian of the children (Minamoto) who is supossed to teach, protect and guide them, but sometimes ends by learning something from them or being protected by them. He, that once had similar problems due to prejudice, wants to raise these children to be good girls that could have the freedom to act and go wherever they want and be whatever they want. He goes from being a completely unconfident guy to be a reliable leader, and passes from being just a fool for the children to be the person they trust the most.
-The antagonist (Hyobu) who has a very detailed and well constructed personality; he has a huge impact on the story of this series and his growth within it is simply marvelous. You have a normal guy, a villian, a victim and a hero, all in one character. It is incredible how the author can change your perspective about this character that much by showing you his personality in such an smooth way.
I could keep writing about the others but I prefer that you judge them by yourselfs by reading them in the manga. If I can add something else in general, it would be about the psychic powers they have; there are mainly 5 types of super powers divided into 2 groups and 7 levels, which gives us infinite possibilities of a particular power for each character, similar to nen in Hunter x Hunter but more detailed.

Enjoyment.

If you're looking for a delightful manga which is light to read but has a lot of content, then this one is what you're looking for. ZKC has a wonderful and deep story, but narrated with the help of different approches. In one arc it can contain a little bit of drama, comedy, mistery, suspense and more. This combination is possible because the main point of the plot is a serious topic, which gives places to several dramatic, tragic and sad situations, but at the same time the daily life of the characters is that of a normal person which is seasoned with a good doze of funny situations. As a result, you'll have chapters that make you laugh like crazy, situations that will give you a lot of suspense and emotion, very touching moments filled with romance, a little bit of healthy/funny ecchi scenes and from time to time sad events that will make you shed some tears.

So if I were to talk about my enjoyment with this series, I could say that I have enjoyed so much that I have read it twice and I can't get tired of it. I still can remeber its chapters with joy. It just has so much to offer that you will find something that make you love it for sure.

Overall

In conclusion, this manga is a 10 out of 10 for me. A perfect combination of good design, wonderful story line, well constructed characters and enough seriousness along with a delightful comedy. All of this makes this manga a true piece of art that everyone could and should read.

I may have made some mistakes while writting this review, or maybe I was not clear enough to explain my thoughts, since this is the first time I write a review and also since english is not my native language, but this manga definitely deserves the effort to write a review about it; so I just hope this review could help you to figure out how awesome this series is.

This is a true masterpiece.