In short, utterly terrible. A thankfully short, z-grade foray into old and tired horror movie cliches that almost look laughably bad with the shonen style art. I would say I really enjoy horror and thriller themed seinen stuff, but more in the vein of episodic, large, almost adventurous tales: bio-meat, cage of eden, kamisama no iutoori and higanjima are all great example of horror seinen done right for me (to varying degrees.) With Ibitsu, all I got was a blah little serial killer story full of dumb plot holes and a twist that I saw coming miles away. The way they kill off characters is so predictable- part of the appeal of many gritty seinen manga to me is the unexpectedness or abruptness with which people meet their ends, even if you know its probably coming. None of that was here. There is no serious resolution here and it simply leaves you where it began, making invalid and useless everything that built up to it- this is true of so many slasher films nowadays. Whats even worse is how derivative of these slashers its truly is as every famous cliche is present: shadows darting forward and friends disappearing, a wacked out backstory involving psychiatric treatment, the old "hold the main character hostage and punish him out of love" routine, and body-switching themes. The characters themselves were the final nails in the coffin - vapid character archetypes with no depth at all. The serial killer and the main character was so typical, so boring,and so unlikable it was just lame. I did not find myself rooting for the hero to escape or on the edge of my seat for what would happen, because it became so tepidly clear what was going to happen. Skip it and watch a classic horror movie instead, same thing but way more entertaining.