The entirety of the anime is about the investigations of mass-suicide. People are seen jumping off buildings, getting themselves run over by vehicles, and shooting themselves.

As brutal as the anime gets is a woman torturing and dismembering another woman with an axe while she's alive. Blood is shown. Although it's off-screen, it is still the most disturbing scene in the entire anime.

The main character finds a piece of paper stained with blood.

The entirety of the anime is about the investigations of mass-suicide. This may be upsetting for some viewers.

The main antagonist may scare some viewers.

The most disturbing scene in the anime is seeing the main antagonist dismember another woman with an axe while she's alive. This scene may be very shocking and upsetting for many viewers.