I love its opening... It's a TRAP for what comes afterwards but still, a beautiful song. So let's get to what comes after the opening. From early on, like from the second episode and onwards we get introduced to a lot of dark themes. Well... I mean, there are the obvious things that are going on and then there are the subplots that the show points at, being all like "There's something reaaally wrong going there! Boy are you gonna have your heart crushed and your faith in humanity completely tarnished when you find out what's going on!" but then it's just like... "you know what? forget this, let's talk about something else" and then we have a completely different unrelated event. Now, I suspect that in the manga there's a certain progression, but this anime series is just jumping around without any actual focus and frankly it got to the last episode and I was like... "dude, there's not even an actual climax here, to the actual story, just some random, super unpleasant, yet coming out of nowhere stuff going on, wtf narutaru?"
I won't say it was a waste of time, but... duuude.... stick to a story, will ya?