Despite over 75% of the series being fairly tame in terms of violence and gore, the last few episodes can be extremely gory, and often times unsettling to watch.
The entire premise of the show is how a small town starts to get overrun by "Shiki", more commonly known as Vampires. Many scenes depict people getting bitten by the Shiki.
The first episode contains decomposing corpses, with a few blood splatters on the floor, as well as maggots infesting in their wrinkled up, decaying skin.
One of the character tells a story to another character about a boy who murders his brother. Not graphic, but a bit of blood can be seen in the vision.