NOTE: My kiriban is still in effect! 9999th pageview gets a free drawing!

...Phew.
Well, that one's going on my list of favourites.
Majin Tantei Nougami Neuro ran a while ago in Shounen Jump and is framed as a sort of murder mystery manga. Every arc has Neuro, a demonic detective who consumes the evil intent created from mysteries, and Yako, a high school girl he's framed as a genius young detective (which she's not) solve a case and reveal the evil intent within the criminal of the week. Once revealed they turn into Yokai-like monsters and exlaim why they commited their crime, at which point Neuro shoots their argument down and eats their mystery. (It makes sense in context.)
The first 1/3 of the series makes it seem very average, with a few interesting characters in Neuro himself and Sasazuka, the police detective who helps them occasionally, and some funny moments with Yako, whose love of food parallels Neuro's love of mysteries. It's okay, but not amazing.
And then the plot really takes off.
Suddenly, starting around chapter 100 but continuing all the way to the end, there's this intricate web of rich characterization and character development. At first it seems like a murder mystery concealing a comedy, but then once you get to this part it becomes clear that even all of that was used to conceal the real drama of the series. It takes on poignant themes like loss and makes them into a beautifully woven story that really couldn't have happened right off the bat. Some might argue that Neuro's slow beginning as a mystery/comedy hinder its flow as a story, but I disagree - we needed to get used to the characters before allowing ourselves to be plunged into the seriousness of the second half. I can't really say anymore - it might spoil the series - but suffice to say that it really is worth readnig all those chapters about random mysteries. Once you get to the end, you'll find yourself not only associating with many of the characters, but also wanting to be more like them and take lessons from them, which is something to be respected in a story.
The art is also very excellent, although a bit hard to deal with at the beginning - it gets better over the course of the story, beginning with some glaring difficulties and ending with an all-around good style. The yokai-inspired 'monsters-of-the-week' that occupy the first half of the story are always something to look forward to (actually, sometimes I'd find myself excitedly wondering what they would end up looking like).
The characters are definitely the strong point of the story, and that becomes more and more apparent as the plot progresses. Still, it's a good read for anyone who likes mysteries, and it is appealing whether you like shounen or shoujo, since it has qualities of both. Definitely worth reading!

You can find it here:
[link]

Well, see you soon, with the next big chunk of sunmoon!
--K