In the 21st century, people with psychic powers (espers), have become fairly common, and the BABEL is the branch of the Japanese government responsible for esper affairs. Japan's 3 most powerful espers are a trio of 10-year old girls, the Children. Hilarity ensues, along with a very awesome plot.

Amidst it all, trying to stop a 100% likely apocalyptic future, is a mentally-gifted but otherwise normal 20-year-old, Minamoto Kouichi. And seriously, if anyone deserves his perfect harem ending as a replacement for that bad future, it is this man. Literally his entire life is lived for the sake of helping his charges, the Children, grow up to be helpful, productive members of society. He endures all manner of hardship over the course of the manga, including but not limited to: 1) Getting taken for a pedophile because he was 2) being sexually harassed by a 10-year-old 3) when the same 10-year-old wasn't slamming him into a wall with her psychic powers (he actually works out several hours a week to build abs to withstand this) because she failed 4) throwing a full-blown temper-tantrum to get him to buy her a toy, all of which pales in comparison to the time when 5) he was possessed by a psychic fly and dunked headfirst into a toilet. He endures this, largely without complaint (even putting his career as a researcher on hold), and does an amazing parenting job, raising the Children the best he can. He doesn't fear them getting angry and will teach life lessons when needed, but he is very conscious of their emotions and avoids hurting them. He gives them a real chance to live like normal kids, which, ironically given their non-normal status, is something they very much needed. His methods come into sharp contrast with those of the Children's previous supervisor, Suma, who had shock collars on them and used them often. Not only that, the manga continues long enough that we do get to see the Children begin to understand what he went through and show their gratitude, in a few heartwarming scenes.

And then there is his nemesis, Hyobu Kyouske, who does something similar – bringing persecuted espers, especially children, into his pro-esper extremist faction (PANDRA) and giving them a home. Hyobu is Minamoto's opposite, something of a Fagin archetype – sure, he's a terrorist, but he's protecting the children of PANDRA from a society that has severely persecuted them. Plus, there are far worse alternatives for a child esper, demonstrated in-universe by Black Phantom, a criminal syndicate that takes traumatized young espers and turns them into killing machines. Some BABEL-side characters recognize this and respect him because of it (to the extent that they pass up some legitimate chances to kill him and end the conflict), and some recognize the good he does but also believe that he does still represent a menace to society and needs to be stopped nonetheless, but their enforcement methods are limited because acting too harshly in dealing with esper criminals might persuade friendly espers (especially the Children) to defect. It's all a very tenuous and tangled moral balance. And it is delicious.

That's the thing about ZKC; the emotional depth is there, but only if you want to look for it. You don't need to look deep into the morals driving each character in order to enjoy the story or the comedy, but it enhances the serious aspect of the story significantly.

It is somewhat difficult to quantify the comedy of ZKC, but it will keep you laughing most of the time. There is certainly a lot of high quality material there, from the one time Minamoto got kidnapped and, ever the dutiful parent, gave his kidnapper a lifestyle makeover, to the other time where the guy with the animal possession ability gets forced into an extremely huggable baby seal body. The variety of character personalities plus the virtually limitless possibilities given by the various types of available superpowers plus an author not afraid to get creative makes for a nearly-flawless humorous repertiore, and this manga delivers. Brilliantly.

This manga is very, very enjoyable, and I recommend it to anyone who isn't totally turned off by lolis, because that might admittedly be it's one sticking point. Even if hate lolis, let this be your one series in that direction. There is fairly little loli fanservice, and there's a lot of fun to be had in reading this manga. Seriously, go read this manga for yourself. It's just crazy awesome both in terms of how hilarious it is and how much sense the characters make.