The story is really interesting. Seriously, the description doesn't do justice to the actual story. Seeing them clash with their wits to make each other confess is just hilarious. If this was a TV show, I'd be on the edge of my seat all the time.
The art is well used, I personally like the style, which is of great quality and renders quite well the universe and characters of the manga, but I've seen better, there are still some things that could be better.
The characters are very well developped and completely over the top, which is quite necessary to considering the challenge of the story, which could have been complicated to exploit with lesser characters. While some of their characteristics are classic, they're pushed to the limit to create intense characters with interesting reactions and making them quite unpredictables.