This is ridiculous, over the top, gory fun and I loved every panel of it.
I'm going to get this out of the way right now-if you're looking for a serious, clever, horror-mystery series, this probably won't be for you. The culprit's over the top villainy combined with the gory deaths and fairly simple detective work makes this come across as an edgy teenager's idea for a mystery-horror series. And yet, all of the things I mentioned are kind of why I had so much fun; it's a simple, gory, over the top supernatural murder mystery. It's not trying to be the manga equivalent to Sherlock Holmes, it's not trying to be philosophical or deep, it's just a manga series about people who want to kill other people, curse gods who give them the ability to do so in the most gruesome ways, and one dude who has to stop them. That's it. If that simplicity is a turn-off, then this isn't the right series for you.
That being said, what I think really shines in this volume (and what I assume will be the case for the whole series) is how it plays up its ridiculous, over the top insanity. The expressions are strong and play up the emotions well in each scene, the paneling is really strong, and the heavy use of shadow in the settings and the characters' expressions really amp up the drama and horror. Not to say this is scary, more so playing up the horror elements. And as stupid as killer cellphones are, it suits a teenage killer really well. I loved being able to see the case progress through the detective's perspective as well as the killer's, even if the mystery part wasn't as mysterious as it could have been. And hell, Saeyama was a fucking trip and I already adore him so much! His assistant, Yamazaki, is adorable as well and I fucking love their dynamic! Also, for a mystery manga, the pacing was really solid and there were enough breaks during the exposition scenes that it didn't feel dense and boring.
So, do I recommend this? Honestly, yes. I know I've shit talked it and I stand by my critiques, but this was a lot of fun! Just in a gory, ridiculous, overly dramatic kind of way rather than a serious murder mystery kind of way. If you want a fast paced, gruesome, murder mystery-horror manga to read, give this one a shot. I thoroughly enjoyed it!