Its so stupid its cringe-worthy. It starts off with 2 characters that are somewhat interesting. A tough butt-kicking martial arts high school girl, and a boy who's stone cold killer. The girl quickly transforms into the comic relief. Really, the author shouldn't have bothered to give her martial arts skills then, its kinda wasted.
So, is it comedy or is it drama? Well, it could loosely be seen as a spoof on other heavy angst ridden super serious manga. Except, the main character is so serious and goes about killing people in such a horrible fashion that its hard to see it as parody. So that makes it a drama with slapstick thrown in. This could be ok, except as other reviewers have pointed out its kinda thrown in sometimes at odd points which doesn't work. Another way to look at it is if this was supposed to be black humor/black comedy, but then it fails there because its not really in line with slapstick. Its like the drama and humor cancel each other out.
The girl also seems to quickly become habituated to the violence and murder going on around her. She doesn't seem to be that horrified after a bit. So what is a smart, strong talented girl supposed to do with a killer on the loose? Mind you this is a killer (in a very serious scene) that attempted to kill her and threatened to kill innocent bystanders, her family and friends. Why, she starts to dispense hugs of course. The power of the hug is not to be underestimated (sarcasm intended). So she evolves from somewhat tough, to comedy relief damsel in distress, to vaguely annoying.
But wait there's more. Aside from the sometimes dumb dialogue there's plenty of contrived scenes. I wont bother with spoilers, its just enough to say that they often give our anti-hero an excuse or justification to kill someone. It wouldn't be so bad except its not subtle, nor is it surprising, its instead clumsy and ham-fisted.
One last thing. Some reviewers have said to give it to chapter 30 and another one said wait till chapter 55 then it gets really interesting. I have not read all the way up to that. You know why? If you have to wait that long for the manga to start getting good, then its a fail. Why waste your time reading 30-50 chapters, instead read something better.
This series does not deserve a 10.