A few graphic verbal references to sexually-transmitted diseases.

One of the more disturbing plot points features a female teacher, who runs the school's radio station, being a sex addict having a graphic affair with a male teacher and openly informing minors about it. A minor girl is urged by her little brother to have an orgy with the teachers; the teacher also implies she masturbates with a microphone as it resembles the male teacher's penis.

A reoccurring gag is that the female main character dreams of having large breasts.

Repeated implications that a boy watches porn; verbal references are made about him "spanking his monkey" and watching something called "Kentucky Girls Gone Wild: Incest Edition".

There are quite a few gay jokes in the series, often poking fun at gay people or being homophobic in nature. It is suggested often that Leo might be gay or "queer" and Momoko often complains that gay people are "heathens" and "anal pirates". Momoko has a cousin who is gay and is seen running a hair salon; he says nothing particularly sexual although Momoko does make rude comments about him.

Construction workers make several sex jokes about each other's sisters.

Contains constant sexual innuendo, with some references being cruder than others albeit brief. Almost all of these moments are played for humor.

Constant talking about one girl's panties. Her white, pink striped, and blue panties are seen throughout the series as two boys constantly attempt to get them shown. She one day decides to wear bike shorts.

A few brief masturbation jokes sprinkled throughout the series directed towards one of the main characters.

A boy tells his sister he felt something sticky in his shorts. She is later shouting about how her little brother shouldn't be having wet dreams at his age.

A running gag is that a main character's mom was a lesbian.

One episode, two girls comment about a boy's butt. One girl later asks what bootylicious means.

There's a constant talk about a boy never getting some.

Mild amounts of blood is present on some of the ghosts' appearances.

Verbal references are made about acts of violence, including murder, rape, a hit-and-run, a drowning in a lake, and a suicide.

A cat is squeezed by a giant monster and nearly killed.

There is a ghost of a statue that is missing skin on half of its body. Showing muscle and intestines below.

People are possessed. And a lot of people eventually try to kill themselves under control of a spirit.

A man is killed in a car accident (off-screen).

Fuck and shit are used alongside lesser profanity like bitch and ass. Homophobic slurs are used as well.

Most, if not all of the profanity in this show is found in the infamous English dub of the series and are not present in the original Japanese version. Words like "Fuck", "Shit" and even slurs like "Fag" are used occasionally, as well as many jokes some may deem offensive.

Alcohol use. References to cannabis and harder drugs.

Constant peril for all characters in the show, as it is about ghosts overrunning an old schoolhouse and causing harm to main or minor characters.

The ghosts are scary a little scary for the younger audience.