Bokke-san

I've maintained for several years now that Yoshiyuki Nishi has the single best creature design in all of manga. Kekkaishi is the closest, but Kekkaishi is resoundingly sane, and Nishi is BAT SHIT. The US version of Muhyo and Roji is neck deep in prime material, the most astounding chunk of the series...and has no buzz at all. Likewise, Bokke-san, his follow up, lasted two volumes, a victim of Jump's ruthless chopping block.
Boy, does it kick off fantastically, though. Nishi jumps right into this one with a mythology that is instantly as fully realized as Muhyo's became, and grounds it all in a story of a boy discovering his true nature that works so ridiculously well it makes everyone else who tries that shit look hamfisted. He succeeds partly by refusing to write the emotions on the nose, partly by constantly undercutting them (the Rock and Roll librarian who gives them key information could undercut fucking anything) and partly by immediately twisting key emotional moments into something else entirely.
It chugs nicely along for a while with a neat urban fantasy vibe, and a few nicely timed fireworks to demonstrate Nishi's flair for spectacle.
But it starts to slip off the rails a little in the second volume. The story accelerates to the point where it just falls apart. You can see his editors pointing at the unspectacular poll results and forcing him to throw in things the story is not yet ready to handle. Things get way too big, way too fast, and the first arc's climax abruptly hits halfway through the second volume. And then it really gets bad.
I've been nursing a theory for a while that a surefire way to get a book canceled even if it is genuinely great is to have too much plot too fast. We saw this with Takei's follow up to Shaman King as well, and a lot of what makes the first volume of Bokke-san so ridiculously strong also makes it very hard for new readers to jump on board as their friends who actually enjoy trying new things recommend it. Muhyo's opening volumes are kind of obviously flawed, but the short story structure allowed him to keep accumulating fans of his fucked up creature design and the book's skewed world view, and kept the book afloat long enough to pull off the epic midsection. Bokke-san's more polished, mature delivery leaves only Nishi's die hard fans reading, and as he starts doing desperate shit like retconning an absent brother in as one of the previously introduced villains, he even lost those.
There's always a lesson to be learned in a canceled manga, but sometimes the only lesson is that people are stupid and don't deserve nice things. In this case, I think we can also say that Jump needs to learn to trust the few artists they have left who have original voices. Jump hasn't had a breakout hit in quite a while, and losing confidence in their second tier oddball books is not an encouraging sign for the overall quality of their line up.