Violence: The violence in the series is very occasional, but what is there is very disturbing. People get eaten and dismembered. You can't see this happening, only the blood pouring. I think at one point you see a bit of brain in a pool of blood. Parts of a mangled corpse is shown in the back of a car. A girl who isn't in her right mind is said to have slashed her wrists, and you see her dead body in a pool of blood. You see serial killer victims in pools of blood a couple times, too.

Sex and Nudity: There's a creepy scene of a guy licking his computer monitor. Another guy pulls bugs only he can see off of people's chests, and it looks like he's groping them, especially since the bugs are located under the clothes. Women's cleavage is exposed during these scenes. A girl witnesses her mother doing you-know-what in a car with who we can assume is a new boyfriend. All you see is brief flashes of their mouths as they make out. A teenage girl is stated to have changed once she lost her virginity.

Theological Themes: Electronic fields have the ability to maintain mysterious creatures. "Evolved" humans with special powers play a prominent role. People are created out of others' memories and feelings. Boogiepop is referred to as a Shinigami. Spoiler: However, she isn't really. It's complicated.

Problematic Themes: The only swear words used are the d-word and the s-word. Their use isn't frequent. No episode features more than two instances of swearing. Most don't have any at all. The only reason I gave it a 4, was that one episode features prominent drug use. It is an evil drug used to control people, and it is portrayed negatively.

Overall: The story is complex and it slowly falls together (with a few gaps). It is truly a horror anime, though the horror mainly comes from general disturbingness, rather than traditional horror elements. It features a lot of philosophical themes, as well. It is really, really confusing, though. I still don't really understand it. I think I'll have to check out Boogiepop and Others and maybe the light novels in order to understand, what's going on.

The characters are all interconnected in some way, even if it's hard to see. Everyone has a few mutual friends here. Most of them have psychological issues, too. I'm not even going to try to explain most of them, since there are so many and there are few recurring characters.

The art is one of my biggest issues. It would have been so much easier to understand the story if the characters weren't all suffering from same-face-syndrome to an extreme. The only way to tell them apart is their hair, and a lot of them have the same hair, too. Not to mention, the characters mainly wear school uniforms and go to the same two schools. It took a lot of brainpower to figure out if you had seen the characters before. The music is very creative, and it definitely doesn't sound typical of a horror series without sounding out of place. There's a lot of techno-beats. I also really liked the ending theme.

I do recommend this series, though for older teens and up, due to complex themes and moments of really disturbing content.