Secco sends Zero a picture of a fish getting a blowjob.

There is a picture of a penis on a book.

Multiple references to dicks, sexual activity and a bit of flirting.

There is a shadow silhouette of a man stabbing another man. No blood is shown but there are splatters of it.

In one scene (jokingly) an animated image of Adolf Hitler is shown shooting himself in the mouth.

"Fuck" and "shit" is used frequently.

Zero said the secret to living a good life was smoking 300 joints a day, a shot of him smoking a joint and blowing smoke into the air.

Occassional drinking, jokes or references.

The fast paced action and moments can be frightening and too intense for some.

The ending is not for sensitive people or even people who hate their life in general.

Zero has many therapeutic moments in the series.

Occassional dark comedy and scenes of Zero getting angry with a vocal earrape effect.