Really, read the manga instead. This isn't necessarily a BAD show, and $XX for a J-drama series is fairly reasonable. But the pacing was awkward, with some parts dragging along and you don't really connect with any of the characters--Hosaka Naoki performance as the main character is sleep-inducing, as is Nakajima Tomoko's (Machi).
At times, the show itself pushes the limits of what can be shown on TV in Japan, though it is generally tame by most standards. I've seen worse on CSI. It's not nearly as gruesome as the box art makes it seem and if you're looking for the standard Miike Takashi shocks, this doesn't really have it. It does, however, have his little touches of weird, dark humor.
Overall, the story is interesting, though I find the manga to be better (and a lot more graphic--no kiddies allowed there!). Much of the miniseries comes straight from the manga, though some storylines have been changed, so if you've read the comics, this drama might be a little more enjoyable.
For the most part, the acting was uneven, but the little bits of humor were a nice, though unnecessary and very unusual, break in the show's slow pace. Osugi Ren (Det. Sasayama) is hilarious when he needs to be, and puts on a great performance, as always. For me, he stole the show. And as a little plus, Miura Rieko (Chizuko) is always nice to look at (for what little time she's on screen).
I would've given it two stars, but I gave it three because of it's relatively low price and interesting story. Most J-drama fans would do well to avoid this and horror fanatics will find this boring.