By Yu Aikawa. Released in Japan by Gentosha, serialized in the magazine Comic Birz. Released in North America by Tokyopop.
I had originally planned to talk a lot about how this was an intriguing volume that showed promise but still had a few flaws, and how I looked forward to seeing how it played out in future volumes. Now, of course, it's a series incomplete at one volume, and unlikely to see anyone pick it up again. As such, the intrigue has worn off a bit and my opinion isn't as good as it was. Not the fault of the manga, though.
This is essentially a supernatural thriller, which tries occasionally to move into the horror vein but doesn't quite make it as it's not scary enough. But then scares aren't really what it's going for. Instead we get more of a tense mystery atmosphere. The lead guy wants nothing to do with the occult, mostly due to past trauma, but naturally the occult keeps drawing him into its nefarious schemes. One of the better things about our hero, Ginji, is that he's genuinely freaked out by this, rather than retreating into passivity like other examples of kids who can see the supernatural. The first chapter has a date he's on go awry when he hospitalizes a haunted house worker trying to scare him. It's a plot tactic designed to put him into debt so he has no choice but to do this, but the sudden violence was genuinely gripping.
The other lead, Ageha, is a bit more stereotypical (and also possesses one of the biggest ahoge I've ever seen in manga, sometimes taking up half the page above her head), but makes for a good balance with Genji's temper. Ageha's secret is revealed halfway through the volume, and surprised me more than it probably should have, but in the end does not particularly change anything, as this volume is more about the mystery.
The mysteries themselves are a combination of one-shot 'monster of the chapter' types, solved by Ageha's powers and Genji's ability to punch things, and the ongoing plotline with Genji's brother and his death (and the possible murder that he committed beforehand). My favorite was the third, which managed to undercut itself nicely (I loved the swim team's reaction once they find out how mundane it is, as if the fact that they'd seen a ghost was now completely normal). The other plot suffers a bit from being stretched out over (presumably) the whole series, so we just get bits of it here, such as the fact that the cute girl interested in Genji may have seen his brother's kill. She's fairly faceless, though. I was amused by Ginji's 'guardian' and his girlfriend, who seem to be overly affectionate in ways I rarely see adults being in a manga like this.
As I noted, I'd probably like this more if I kept reading it - it was good enough for me to have ordered Volume 2. As it is, though, I'm not quite intrigued enough to try to track down Japanese volumes from 6 years ago. Still, if you like supernatural stuff and don't mind that it's cancelled, Butterfly might be up your alley.