Mostly lacking nudity, but some sexual undertones and mild nudity are present.

A boy acts like a pervert to one of the twins at times, for comedic effect.

A boy is implied to get a hard-on, for comedic effect.

A strange disease causes a young man to have bizarre erotic fantasies involving his classmates, including three girls who're no more than 13 years old.

A boy crossdresses sometimes for comedic effect.

A boy is seen naked from behind. His buttocks can be clearly seen.

Rena is seen naked from behind. Her buttocks can be clearly seen.

Multiple scenes of strong bloody violence, including sequences of brutality, torture, sadism, and murder. Copious amounts of bloodspray throughout, with some moderately strong gore. However, in the censored version of the anime, such violence is present, but darkened, and very little details are shown.

One of the main characters is a major sadist who provides abundant violence.

A girl and a woman fight brutally. The woman starts to strangle the girl, but the latter frees herself by cutting the woman's stomach with a piece of glass. She afterwards beats her to death with a steel pipe. Her mangled, disfigured face, with missing teeth and copious blood loss, is seen briefly but graphically. The woman is then chopped up and hidden in a fridge.

In a low-light situation, two girls are beaten to death by a boy with a baseball bat. Their mangled bodies are briefly displayed onscreen.

A girl is forced to use a device to tear off her own fingernail. The fingernail is seen severed and a bloody wound is also seen. She cannot bring herself to tear another and is restrained. It's implied that two more fingernails are torn off. The partially healed wounds are seen later.

Two girls fight, and one is injected with a syringe.

It's implied a man has fifteen needles driven into his hand. Later, his bagged corpse is seen with the nailed hand.

A boy and girl fight, with a baseball bat and a cleaver respectively. There is no blood or contact violence though.

A girl tazers multiple people, with one old woman dying as a result. Her corpse is then repeatedly whipped in anguish.

A man is seen hung.

A character claws their throat out. Blood sprays everywhere.

A girl has her hand repeatedly slammed in a door.

A girl's dress snags on something and she falls from the roof of a building to her death.

Books portraying ancient torture rituals are seen. One picture shows a man being slowly disemboweled by a winch, with his guts being torn out of his body while he's still alive. Such torture is mentioned a few times.

Multiple scenes of near-death choking.

A girl stabs a boy in the stomach. Blood begins to seep through his shirt. He doesn't die.

A man has an axe impaled in their head by a girl. The top of their head splits up a little (graphic). His body is buried gruesomely.

In a disturbing scene, a girl repeatedly claws at her wrists and neck, imagining, because of a hallucinogenic drug, that maggots are crawling around such areas. Her wounds are seen bandaged later.

Some nosebleed scenes.

A girl cuts her finger with a knife.

A man is shot offscreen.

A boy is hit in the head with a chair. His head starts bleeding.

A soldier commits fratricide.

A man dies on a hospital bed (very bloody).

Two police officers are shot in the head by a sniper (partially offscreen).

Five more children are shot in the head (partially offscreen).

A crowd of people are trapped in a building and gassed to death. A few escape and are shot (partially offscreen).

A bus driver has a heart attack. The bus goes out of control and severely injures several people.

A man is beaten to death and dismembered (partially offscreen).

A girl's blood is drawn.

A girl is hit by a truck (offscreen but bloody).

Moderate use of "damn", "dammit", "hell", and "bastard".

There are a few uses of the "F"-word in the subtitled version.

"Pussy"

"Bitch"

"Shit"

"Pisses me off"

"Slut"

Language depends on the dub or subtitles.

One of the characters is frequently seen smoking.

A man is often seen drunk and violent.

(Deleted. Personal opinions about ratings are not appropriate for the Parents Guide.)

This anime is extremely intense throughout, both in terms of violence and psychology.

It contains numerous strong, intense, bloody scenes of torture and murder.

The themes of paranoia and insanity are ever-present throughout the series.

There are many instances of violence inflicted by children, taken out on children, or witnessed by children, including a preteen suicide and a torture scene with a sadistic teenager and a young girl.

There is a recurrent theme of abuse on a orphaned little girl by a family member.

Another main theme is the supernatural, which is portrayed in a very creepy way.

Some other strong themes are bullying, revenge, stalking, kidnapping, and drugs.