Just discovered why you only read five chapters, and there was a pretty good chance for a bit there that I was only going to read five chapters too - because chapter 5 is when we discover that
spoiler
Kizutaka is a freaking psychopath.
I'm going to give it a chance though - NISIOISIN hasn't let me down yet.
I can't say yet. By gritting my teeth and forging on,I only managed to make it through three more chapters last night, and as yet there's no sign that he's going to change, and he really is an utterly loathsome character. I'm not giving up yet though so I'll let you know.
First, it's notable that it took this long to read 28 chapters, and a reflection of the fact that it was a slog.
And it's either the case that the "last chapter" bit is misleading or that it was entirely unexpectedly axed, since the story isn't even close to wrapping up.
I really can't recommend it. It's not entirely awful, and there's still some intriguing mysteries that might shift the tone a bit, but as it is the story is too rushed and superficial, and pretty much every character, and most notably the protagonist, are all some variety of loathsome POS. In fact, the few characters who weren't utterly loathsome were apparently there solely to be murdered, and just as likely murdered by the protagonist as by the supposed villains.
I'm not sure if I'm going to keep following it or not. There's one specific mystery that's been broadly hinted at that could undermine everything - could make the protagonist manipulated and/or delusional instead of what he appears to be - just a smug, self-absorbed and entirely conscienceless POS. I still want to give NISIOISIN the benefit of the doubt but...